Answer:
To get the number of atoms in this sample, we first need the number of moles of lead in 11.3 grams
Number of moles of Lead:
Molar mass of lead = 207 grams / mol
Number of moles = given mass / molar mass
Number of moles = 11.3 / 207
Number of moles = 0.05 moles
Number of atoms of lead in 11.3 gram sample:
Number of atoms = Number of moles * avogadro's number
Number of atoms = 0.05 * 6.022 * 10²³
Number of atoms = 5 * 10⁻² * 10²³ * 6.022
Number of atoms = 30.11 * 10²¹
11.3 g block of lead contains 3.29×10²² atoms
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.022×10²³ atoms. Thus,
1 mole of lead = 6.022×10²³ atoms
Recall:
1 mole of lead = 207 g
Thus,
207 g of lead = 6.022×10²³ atomsWith the above information in mind, we can obtain the number of atoms in 11.3 g block of lead as illustrated below:
207 g of lead = 6.022×10²³ atoms
Therefore,
11.3 g of lead = (11.3 × 6.022×10²³) / 207
11.3 g of lead = 3.29×10²² atomsThus, 11.3 g block of lead contains 3.29×10²² atoms
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Which type of equilibrium is more likely to omit substances from the equilibrium constant expression
The question is incomplete, the complete question is;
Compare Homogeneous and Heterogeneous Equilibria Question Which type of equilibrium is more likely to omit substances from the equilibrium constant expression? Select the correct answer below: O homogeneous equilibria O heterogeneous equilibria O a and b are equally likely O there is no correlation
Answer:
heterogeneous equilibria
Explanation:
In a heterogeneous equilibria, there are species of different phases present in the equilibrium expression. Some of these heterogeneous substances may be pure solids.
Remember that the solids and pure liquids are eliminated from the final equilibrium expression.
Thus, when writing equilibria involving heterogeneous substances, solids and pure liquids do not appear in the final equilibrium expressions.
What is the concentration (g/L) of an albumin solution made by mixing 0.20 mL of 6.0 g/L solution with 2.72 mL BCG reagent? Assume volumes are additive.
Answer:
0.41g/L
Explanation:
To find the concentration of the albumin in the mixture we need to find the mass in grams and the volume in liters of the solution:
Mass of albumin:
0.20x10⁻³L * (6.0g / L) = 1.2x10⁻³g of albumin
Volume of the solution:
0.20mL + 2.72mL = 2.92mL = 2.92x10⁻³L
Thus, concentration of albumin is:
1.2x10⁻³g of albumin / 2.92x10⁻³L =
0.41g/LOn the basis of your understanding of the general solubility guidelines, predict which of the following substances are likely to be soluble in water.
a. zinc chloride
b. cobalt(III) sulfide
c. lead(II) nitrate
d. chromium(II) hydroxide
e. lead(II) sulfate
f. magnesium carbonate
g. sodium iodide
h. ammonium carbonate
Answer:
ZnCl2
sodium iodide
ammonium carbonate
Pb(NO3)2
Explanation:
Substances that dissolve in water can be accurately determined using the solubility rules.
According to the solubility rules, all nitrates are soluble. This implies that lead II nitrate is also soluble in water.
Similarly, all chlorides are soluble in water hence ZnCl2 is soluble in water.
Sulphates are soluble except those of Pb, Ba, Ca and Mg.
Also, NaI is highly soluble in water.
Lastly, all carbonate salts are insoluble except those of sodium, potassium and ammonium. Hence ammonium carbonate is soluble in water.
explain how sound and vibration are related ?
Answer:
because they can create noise
Explanation:
sounds is through music or songs but vibration is just quick vibrate music, not quite sure , it's just my instinct, lol
Determine the percent ionization of a 0.225 M solution of benzoic acid. Express your answer using two significant figures.
Answer:
1.68% is ionized
Explanation:
The Ka of benzoic acid, C₇H₆O₂, is 6.46x10⁻⁵, the equilibrium in water of this acid is:
C₇H₆O₂(aq) + H₂O(l) ⇄ C₇H₅O₂⁻(aq) + H₃O⁺(aq)
Ka = 6.46x10⁻⁵ = [C₇H₅O₂⁻] [H₃O⁺] / [C₇H₆O₂]
Where [] are concentrations in equilibrium
In equilibrium, some 0.225M of the acid will react producing both C₇H₅O₂⁻ and H₃O⁺, the equilibrium concentrations are:
[C₇H₆O₂] = 0.225-X
[C₇H₅O₂⁻] = X
[H₃O⁺] = X
Replacing:
6.46x10⁻⁵ = [X] [X] / [0.225-X]
1.4535x10⁻⁵ - 6.46x10⁻⁵X = X²
1.4535x10⁻⁵ - 6.46x10⁻⁵X - X² = 0
Solving for X:
X = -0.0038. False solution, there is no negative concentrations.
X = 0.00378M. Right solution.
That means percent ionization (100 times Amount of benzoic acid ionized over the initial concentration of the acid) is:
0.00378M / 0.225M * 100 =
1.68% is ionizedA cell must work to maintain a stable internal environment. It is also important for the environment around the cell to be stable. What reasoning explains what happens when the concentration of water inside a cell is lower than the concentration of water outside the cell?
The cell loses nutrients.
The cell splits and creates two new cells.
The cell gains too many lipids and carbohydrates.
The cell either loses water and dries up or gains too much water and bursts.
(science 7th grade)
Answer: the last one
Explanation: if a cell has too little water, it will begin to function incorrectly, and if a cell has too much water it will burst.
Identify which location in the periodic table you would have the
largest atomic radii.
Answer:
left to right across a period when it decreases and when it increases top to bottom in a group,
hope i helped
Determine whether each statement describes a solution of a strong electrolyte, weak electrolyte, or non-electrolyte.
1. Contains a partially dissociated solute
2. Has the highest conductivity
3. Contains a complete solute
4. Contains a completely dissociated solute
5. Has a medium level of conductivity
6. Has little or no conductivity
Answer:
Strong electrolytes-2,4
Weak electrolyte-1,5
Non electrolyte- 3,6
Explanation:
The statements were labeled according to whether they define strong electrolytes, weak electrolytes or non electrolytes.
Strong electrolytes are completely dissociated in solution and form highly ionic solutions.
Weak electrolytes have medium conductivity and do not completely dissociate in solution.
Non electrolytes do not dissociate in solution and their solution does not conduct electricity.
1. Weak electrolyte solution: it contains a partially dissociated solute.
2. Strong electrolyte solution: it has the highest conductivity.
3. Non-electrolyte solution: it contains a complete solute.
4. Strong electrolyte solution: it contains a completely dissociated solute.
5. Weak electrolyte solution: it has a medium level of conductivity.
6. Non-electrolyte solution: it has little or no conductivity.
A solution can be defined as a homogenous mixture that contains two or more substances.
In Chemistry, there are three (3) main types of solution and these include:
1. Weak electrolyte solution: this is a type of solution in which only a small amount of dissolved solute exists as ions because it partially dissociates into its constituent anions and cations.
It has a medium level of conductivity.It contains a partially dissociated solute.2. Strong electrolyte solution: this is a type of solution that contains only ions but no molecules of the electrolyte because it completely dissociates or ionizes in a solution.
It contains a completely dissociated solute.It has the highest conductivity.3. Non-electrolyte solution: this is a type of solution that do not dissociates or ionizes in a solution.
It has little or no conductivity.It contains a complete solute.Read more: https://brainly.com/question/24057916
3. How can the force of gravity affect weight?
A car travels for 0.5 hours and goes 25 miles. What is the car's speed? (Remember sad + t)
Answer:
s = 22.352 m/s
Explanation:
Given data:
Time taken = 0.5 hours
Distance cover = 25 miles
Car speed = ?
Solution:
First of all we will convert the units.
1 hour = 3600 sec
0.5 hr ×3600 sec / 1hr = 1800 sec
miles to meter:
25 mi × 1609 m/ 1 mi = 40233.6 m
Formula:
s = d/t
s = speed
d = distance
t = time
Now we will put the values in formula.
s = 40233.6 m / 1800 sec
s = 22.352 m/s
Consider the reaction when aqueous solutions of chromium(III) chloride and ammonium sulfide are combined. The net ionic equation for this reaction is
Answer:
2Cr³⁺(aq) + 3S²⁻(aq) ----> Cr₂S₃(s)
Explanation:
When aqueous solutions of chromium(III) chloride and ammonium sulfide are mixed together, chromium (III) chloride and ammonium sulfide undergoes a double displacement reaction to produce chromium (iii) sulphide as a precipitate and ammonium chloride which remains in solution.
The general equation of the reaction is given below:
2CrCl₃(aq) + 3(NH₄)₂S(aq) ----> Cr₂S₃(s) + 6NH₄Cl(aq)
The net equation of the reaction is given below:
2Cr³⁺(aq) + 3S²⁻(aq) ----> Cr₂S₃(s)
Calcium hydroxide is titrated with nitric acid. What volume of 0.0200 M calcium hydroxide is required to neutralize 35.00 ml of 0.0500 M nitric acid?
Answer:
43.75 ml
Explanation:
Given that the equation of the reaction is;
2HNO3(aq) + Ca(OH)2(aq) ---> Ca(NO3)2(aq) + 2 H20(l)
Concentration of acid CA= 0.05 M
Concentration of base CB = 0.02 M
Volume of acid VA = 35.00ml
Volume of base VB= ???
Number of moles of acid NA= 2
Number of moles of base NB=1
From
CAVA/CBVB= NA/NB
Making VB the subject of the formula;
VB= CAVANB/CBNA
VB= 0.05 × 35 × 1/ 0.02 × 2
VB=1.75 /0.04
VB= 43.75 ml
In which of the following atoms are valence electrons in the lowest average potential energy states?
Cl
Br
F
I
Answer:
C) F
Explanation:
Valence electrons are the electrons present in the outermost shell of an atom and have the highest energy level of an atom whereas electrons at ground state or lower orbitals have less potential energy.
This is so because orbitals nearby nucleus are strongly bonded with the atomic nucleus and have less energy than an outermost shell.
So, the potential energy states of an atom depend on the number of orbitals. In the given options fluorine with atomic number 9 has less number of orbitals that is 2 orbitals and valence electrons will be present in second orbitals, so fluorine will have the lowest average potential energy states.
Hence, the correct option is "C) F".
An unknown compound contains only carbon, hydrogen, and oxygen (CxHyOz). Combustion of 5.50 g of this compound produced 8.07 g of carbon dioxide and 3.30 g of water.
Required:
a. How many moles of carbon, C, were in the original sample?
b. How many moles of hydrogen, H, were in the original sample?
Answer:
a. 0.183 mol C
b. 0.366 mol H
Explanation:
Assuming total combustion, all of the carbon in the unknown compound turned into carbon dioxide, CO₂.
So first we calculate the CO₂ moles produced, using its molecular weight:
8.07 g CO₂ ÷ 44 g/mol = 0.183 mol CO₂This means in the unknown compound there were 0.183 moles of carbon, C.
Conversely, all of the hydrogen in the unknown compound turned into water, H₂O.
Calculating the H₂O moles:
3.30 g ÷ 18 g/mol = 0.183 mol H₂OWe multiply the water moles by two, as there are 2 H moles per H₂O mol:
0.183 * 2 = 0.366 mol H.How many moles are in 9.8 x 1024 atoms of calcium?
Explanation:
no of moles = no of atoms ÷ avogadro's number
= (9.8×10^24) ÷ (6.02×10^23)
Atoms of two different elements must have different
electrical charges.
numbers of neutrons.
atomic numbers.
energy levels.
GIVE EXPLANATION!!!!
Answer:
c atomic numbers
Explanation:
hope this helps
Answer:
atomic numbers
Explanation:
In order for two atoms to be different, they have to have a different number of protons. Protons are represented by the atomic number. Thus, atoms of two DIFFERENT elements must have different atomic numbers.
I took the test and got 100%
Hope this helps!
Prior to science lab, Maria had been drinking a can of soda. When she walked into the lab she set it down on the hot plate at her station. She heard a liquid beginning to boil, and realized that the previous students had forgotten to turn off the hotplate and the boiling noise was from the remaining soda in the can. Without thinking, she picked up the can with her bare hands, and put it upside down into the sink which was half full of liquid. Immediately the can crushed as though it was going to be recycled. What do you think is happening to the soda and air in the can? Support you claim in Question 4, by explaining why you think it is happening. Formulate your hypothesis for the problem. Critique Maria’s laboratory safety procedures.
Answer:
See explanation
Explanation:
When the temperature was increased, the pressure of the gas in the can was increased.
When Maria removed the can and placed it in cold liquid, the decrease in temperature led to a corresponding decrease in pressure of the gas inside the can hence the can was crushed.
Hypothesis: The pressure of the gas in the can is directly proportional to temperature.
Maria was careless about the experiment. She ought to have first checked whether the hot plate was off before placing the soda can. Secondly,she should not have immediately plunged the soda can into liquid because it will shrink due to decrease in pressure. She should not also have removed the soda can with bare hands to avoid getting burns and blisters.
Give an example of a substance that is MORE dense in its solid state when compared to its liquid state.
Answer: Wax
Explanation:
Density is defined as the mass contained per unit volume.
[tex]Density=\frac{mass}{Volume}[/tex]
Usually solids are more denser than liquid, as molecules in solid are more strongly packed and thus have more mass per unit volume.
Liquids on the other hand contain molecules which are less tightly bound and thus thus contain less mass per unit volume as compared to solid.
Example: Solid wax is more denser than liquid wax.
When a solution of beryllium sulfate and calcium hydroxide are mixed, what precipitate if any is formed
Answer:
CaSO₄ (calcium suflate) is the precipitate formed
Explanation:
We can think the reactants:
BeSO₄ → Beryllium sulfate
Ca(OH)₂ → Calcium hydroxide
The reaction is:
Be₂SO₄ + Ca(OH)₂ → CaSO₄ ↓ + Be(OH)₂
We call it as a double-replacement reaction because two ions exchange places from 2 compounds to form two new compounds.
Sulfates can always make precipitate with the elements from group 2, Ca, Ba and Mg.
Hydroxides from group 2 are solubles, so we complete states:
BeSO₄ (aq) + Ca(OH)₂ (aq) → CaSO₄ ↓ (s) + Be(OH)₂ (aq)
For a water in equilibrium with the atmosphere, a pH of 2.0, and a total soluble iron concentration of 1 mg/L, calculate the concentrations of Fe2+(aq) and Fe3+(aq).
Answer:
Fe^2+(aq) = 4.51 × 10^-11 M
Fe3+(aq) = 1.79 × 10^5 M.
Explanation:
So, the first thing to do is to to write out the chemical reaction showing the ionic reaction of the chemical species present in the chemical reaction;
4Fe^2+ (aq) + O2(g) + 4H^+ <---------------------------> 4Fe^3+(aq) + 2H2O(l).
The next thing to do is to determine or calculate for G° and the equilibrium constant,kc. Thus, the value of G° = 4(-4.6) + 2(-237.18) - {4(-78.87)} = -177.28 kJ/mol.
Therefore, the equilibrium constant = e^-∆G°/RT = 1.19 × 10^31.
Therefore the value for Fe^2+ and Fe^3+ can be determine as;
NB=> Recall that [Fe^3+]/[Fe^2+] = kc [(Po2) (H^+)^4]^1/4.
Also, 1/ 55850 = 1.79 × 10^-5 M.
[Fe^2+] + [Fe^3+] = 1.79 × 10^-5. -------(1).
Therefore, [Fe^3+]/[Fe^2+] = kc [(Po2) (H^+)^4]^1/4. = [Fe^3+]/[Fe^2+] = [ 1.19 × 10^31 × 0.2095 × (10^2)^2] ^1/4 = 3.97 × 10^5.
Therefore, [Fe^3+]/[Fe^2+] = 3.97 × 10^5.
[Fe^3+] = 3.97 × 10^5[Fe^2+].
Hence, using the equation (1) above we can determine the value of the species.
[Fe^2+] + [Fe^3+] = 1.79 × 10^-5
[Fe^2+] + [Fe^2+] = 1.79 × 10^-5.
[Fe^2+] + 3.97 × 10^5[Fe^2+] = 1.79 × 10^-5.
[Fe^2+] = 4.51 × 10^-11 M.
Therefore, we will have [Fe^3+]/[Fe^2+] = 3.97 × 10^5.
Thus, [Fe^3+] = [Fe^2+] × 3.97 × 10^5. = 1.79 × 10^5 M.
Which are replenished MORE quickly than they are used?
A. energy resources
B. material resources
C. renewable resources.
D. nonrenewable resources
Answer:
C renewable
Explanation:
because renewable energy repleneshes itself, therefore the quickest
Renewable resources are replenished MORE quickly than they are used (option C).
Renewable resources can be defined as a type of resource that cannot be depleted, thereby supplying a constant source of such resources.A source of renewable energy can be used to obtain unlimited amounts of energy without damaging the environment.Renewable sources of energy include solar energy, wind energy, hydrothermal energy, etc.In conclusion, renewable resources are replenished MORE quickly than they are used (option C).
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Which of the following rock will form if it is broken into sediment then emulsified over a long period of time?
Sedimentary rock
Magma rock
Metamorphic rock
Igneous rock
Can someone help me PLEASE?!!! will mark brainliest and also the rest!!!
can someone write them in their OWN words?!!! PLEASE!!! (this is for Science)
THANK YOU SOOO MUCH FOR WHO EVER HELPS ME!!! REALLY APRICIATE!
THX :)
Answer:
Mark as brainleist answer and thanks this answer
Why is the atomic theory a theory and not a law?
10 Points)
A theory is the best possible explanation based on all existing evidence.
A theory is a pattern in nature.
O A theory does not change.
O A theory is more important than a law.
Answer: A) A theory is the best possible explanation based on all existing evidence
A law in physics and chemistry is a description of what is going on. For instance, newton's law of motion helps us find out an objects acceleration if we know its mass and the force applied. The theory of gravity on the other hand is the best guess we make as to why objects with mass are attracted to one another.
Theories change over time if new evidence is found that contradicts the old theory. Saying "a theory is more important than a law" is subjective, and I would argue that both are equally important in their own way.
The atomic theory a theory is the best possible explanation based on all existing evidence. The correct option is A.
What is a theory?The word theory renowned as to an untested hunch or one can say a guess with not having a supporting evidence.
A theory, has nearly the opposite implications for scientists. A theory is a well-supported explanation of an innate phenomenon that can encompass laws, hypotheses, along with facts.
Theories are developed to elaborate, predict, as well as comprehend phenomena, also to challenge and extend existing understanding within the constraints of critical boundary assumptions.
A theory does not become a scientific law as new or better evidence accumulates.
The theories are explanations, as well as laws are patterns located in large amounts of data that are frequently expressed as an equation. A theory will always be a theory in all aspect, and a law will always be a law.
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What type of crust type does transform boundary have?
Answer:
Thus, at convergent boundaries, continental crust is created and oceanic crust is destroyed. Two plates sliding past each other forms a transform plate boundary. Natural or human-made structures that cross a transform boundary are offset—split into pieces and carried in opposite directions.
Explanation:
When the following redox equation is balanced with smallest whole number coefficients, the coefficient for the iodide ion will be _____.
I–(aq) + NO3–(aq) → NO(g) + I2(s) (acidic solution)
Answer:
When the following redox equation is balanced with smallest whole number coefficients, the coefficient for the iodide ion will be __6__.
Explanation:
From the redox equation, we can see that NO₃⁻ is reduced to NO (from oxidation state +5 to +2), whereas I⁻ is oxidized to I₂ (from oxidation state -1 to 0). The half reactions are balanced with H⁺ (acidic solution), as follows:
Reduction : 2 x (NO₃⁻(aq) + 3 e- + 4 H⁺ → NO(g) + 2 H₂O)
Oxidation : 3 x (2 I⁻(aq) → I₂(s) + 2 e-)
----------------------------------------------------------------------
Total equation: 6 I⁻(aq) + 2 NO₃⁻(aq)+ 8 H⁺ → 3 I₂(s) + 2 NO(g) + 4 H₂O
That is the redox equation with the smallest whole number coefficients.
Accordin to this, the coefficient for the iodide ion (I⁻) is: 6.
The given redox equation is balanced with the smallest whole-number coefficients, the coefficient for the iodide ion will be 6.
Redox reactionRedox reaction is the reaction in which oxidation and reduction both occur simultaneously.
From the redox equation, we can see that NO₃⁻ is reduced to NO (from oxidation state +5 to +2), whereas I⁻ is oxidized to I₂ (from oxidation state -1 to 0).
The half reactions are balanced with H⁺ (acidic solution), as follows: Reduction : 2 x (NO₃⁻(aq) + 3 e- + 4 H⁺ → NO(g) + 2 H₂O)
Oxidation : 3 x (2 I⁻(aq) → I₂(s) + 2 e-) ----------------------------------------------------------------------Total equation: 6 I⁻(aq) + 2 NO₃⁻(aq)+ 8 H⁺ → 3 I₂(s) + 2 NO(g) + 4 H₂O
That is the redox equation with the smallest whole number coefficients.
According to this, the coefficient for the iodide ion (I⁻) is: 6.
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What happens to a person's weight on smaller and larger planets?
Answer: The size actually does not matter. But planets with smaller mass will have less gravity decreasing their weight. Other for larger mass planets, more mass is more gravity which is also more weight.
Explanation:
In science class, a student is given a copper cylinder to investigate. The student measures the mass of the cylinder as 53.76 grams. The
student measures the volume of the copper as 6 cm. Which additional property of the copper can the student determine from these
measure
Answer:
From these two values, i.e. mass and volume, density of the copper cylinder can be calculated.
Formula of density is :
Density = Mass / volume.
Now we have mass: 53.76g and volume 6cm³
Density = 53.76 / 6
Density= 8.96 g/cm³
A cube of aluminum measures 3 cm on each side and weighs 81 g. What is its density? (HINT: find the volume of the block first)
D=
M=
V=
Answer:
27
Explanation: volume-3 times 6=18 /mass- 81 times 6= 486.... 486 divided by 18 = 27.... a cube has 6 sides.
The density of a substance is simply defined as the mass of the subtance per unit volume of the substance.
[tex]Density = \frac{Mass }{Volume }[/tex]
To obtain the density of the aluminum, we'll begin by calculating the volume of the aluminum. This can be obtained as follow:
From the question given above, each side of the aluminum cube measures 3 cm. Thus,
Length (L) = 3 cm
Width (W) = 3 cm
Height (H) = 3 cm
Volume = Length × Width × Height
Volume = 3 × 3 × 3
Volume = 27 cm³Therefore, the volume of the aluminum is 27 cm³
Finally, we shall determine the density of the aluminum. This can be obtained as follow:
Mass = 81 g
Volume = 27 cm³
Density =?[tex]Density = \frac{Mass }{Volume }\\\\Density = \frac{81}{27}[/tex]
Density = 3 g/cm³Therefore, the density of the aluminum is 3 g/cm³
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The weight of the purified caffeine is often much lower than the weight of the crude caffeine. Explain why the percent recovery is frequently low?
Answer:
see explanation
Explanation:
When caffeine is purified, the impurities are removed, these impurities are responsible for the greater mass of pure caffeine compared to the mass of the pure sample.
The percent recovery of caffeine is frequently low because some caffeine is often left behind in the solvent during the process of recrystallization.
Secondly, since caffeine is a sublime substance, some caffeine may be lost o sublimation leading to a low percent recovery of pure caffeine.
