How are stars and comets different?
A. A star has a solid rock and gas surface, while a comet has tail of dust and gas.
B. A star has a tail of dust and gas, while a comet has a solid rock surface.
C. A star is made up of burning gases, while a comet is made up of ice, gases, rocks, and dust.
D. A star is made up of ice, rocks, and dust, while a comet is made up of burning gases.
Elements are simple ___
made of the same type of ____. They cannot be ___
down chemically. There are about 118 known
elements and most elements are ___
They are ____ in
appearance and are good ___ of heat and _____. Compounds are made from ___
or more elements chemically _____.
Answer:
particles
atoms
broken
isotope
conductors
electricity
element
combined
What is the pH of a solution with a H+ ion of 2×10-¹²?
Answer:
11.7
Explanation:
The pH is the negative logarithm of the concentration of H+ ions. If the concentration is 2×10-¹² the the pH will be -log(2×10-¹²) which is 11.698 which can be round up to 11.7.
Ammonia , NH3, equation stocihiometric balance
LID
Question 3
20 pts
How many atoms of aluminum can be produced by the decomposition of 31.5 g of
Al2O3?
(Hint: Write and balance the equation first.)
09.30 x 10 22 Al atoms
1.86 x 1023 Al atoms
O 7.44 x 1023 Al atoms
O none of these
O 3.72 x 1023 Al atoms
I need help
Answer:
See Down
Explanation:
2Al2O3 = 4Al + 3O2 (Decomposition)
31.5/101.961g = 0.3089mol
(0.3089mol/2) * 4 = 0.61788 mole of Al
0.61788 mole * 6.022x10^23 atoms/mol = Your answer
How does a lithium atom form the most stable ion?
Answer:
im absoulutely positive it is C
What is the molar mass of Ammonium Carbonate?
Answer:
96.09 g/mol
Explanation:
The percentage by mass of oxygen in a compound containing potassium, chlorine, and oxygen was determined experimentally. The technique used follows. solid (KClo compound is weighed. Then it is heated in a crucible. The The solid decomposes to produce oxygen gas and a salt. Because the oxygen escaping, mass of the original solid decreases. From the mass of oxygen lost and mass is the the percentage by mass of oxygen in of the original the original compound is determined. KClyo. (s) salt (s) O (g A student performs five trials and determines the following by mass of oxygen in the compound (KCLO) by mass of oxygen Trial in the compound 38.933 38,940 38,892 38.900
a. Determine the average experimental percentage oxygen in the compound. by mass of 30.933
b. If the actual value of the percentage by mass ofoxygen in this compound is 39.13 determine the percentage error.
Answer:
See explanation
Explanation:
The percentage by mass of oxygen is defined as;
Mass of oxygen/ molar mass of the compound * 100/1
The average percentage by mass of oxygen = 38.933 + 38.940 + 38.871 + 38.892 + 38.900/5
The average percentage by mass of oxygen = 38.907
Percentage Error = (|accepted value – experimental value| \ accepted value) x 100%
Percentage Error = 39.13 - 38.907 / 39.13 * 100
Percentage Error = 0.57%
I'LL MARK YOU BRAINLIEST! Please help me balance these chemical reactions. (I'M NOT IN COLLEGE, I'M IN 10TH GRADE) Please help me
Answer:
1. H2 + Cl2 => 2HCl
2. Na2S + 2HCl => 2NaCl + H2S
3. 6HCl + 2Al => 2AlCl3 + 3H2
4. C3H8 + 5O2 => 3CO2 + 4H2O
5. C6H12O6 + 6O2 => 6CO2 + 6H2O
6. 4C12H23O11 + 49O2 => 48CO2 + 46H2O
7. 4NH3 + 7O2 => 4NO2 + 6H2O
8. 2Mg + 02 => 2MgO
hope it helps
A balloon has been filled to a volume of 1.90 L with 0.2 mol of helium gas. If I add helium until
0.6 mol of helium is in the balloon, what is the new volume of the balloon?
0.63 L
5.7 L
15.8 L
0.06 L
Answer:0
.63
Explanation:
What is the independent and dependent variable?
a. It is likely that you have observed a sealed soda can left out in a hot car expands. Based on the notion that gas escapes a liquid at high temperatures, a student chose to investigate the amount of dissolve oxygen in a local pond over a 12-month period.
b. Sulfur dioxide is a commonly used preservative in wine as it prevents oxidation and bacterial growth. A wine producer would like to explore if pH affects the solubility of SO2 in the wine, and therefore decides to measure the SO2 in the wine solution over a range of pH values.
c. The H2SO4 electrolyte concentration impacts the performance of lead-acid batteries, commonly used as car batteries. A researcher wishes to determine the optimal H2SO4 concentration for the best performance of the battery, as measured by the voltage output.
Answer:
The independent and dependent variable for the following are as follows:
a. Temperature and amount of dissolved oxygen
b. pH and SO2 solubility/amount
c. H2SO4 concentration and voltage output/performance of battery
Explanation:
In an experiment;
- Independent variable is the variable that the experimenter manipulates or changes in order to get a measurable response.
- Dependent variable is the variable that the experimenter measures based on its response to changes made to the independent variable.
A). In this experiment, a student is trying to investigate the amount of dissolved oxygen in a local pond in response to changes in temperature. Hence, the independent variable is the TEMPERATURE while the dependent variable is the AMOUNT OF DISSOLVED OXYGEN.
B). In this experiment, a wine producer would like to explore if pH affects the solubility of SO2 in the wine by measuring the amount of SO2 in the wine solution over a range of pH values. Hence, the independent variable is the pH while the dependent variable is the SO2 SOLUBILITY OR AMOUNT.
C). In this experiment, a researcher wishes to determine the optimal H2SO4 concentration for the best performance of the battery, as measured by the voltage output. Hence, the independent variable is the CONCENTRATION OF H2SO4 while the dependent variable is the VOLTAGE OUTPUT or PERFORMANCE of the battery.
A small, rocky island is home to a community of organisms. They include birds,
insects, lichen, moss, shrubs, and small plants. Flooding during a storm damages the
ecosystem, except for the lichen and moss.
Two students observe the changes to the island community during and after the
storm. Chandra classifies the changes as primary succession, whereas Brenda
classifies them as secondary succession. Which argument is supported by the
evidence?
Brenda argument is supported.
Here moss and lichens are still there after the flood which will recolonize the colony once there.
What is primary successionPrimary succession is ecological succession that begins in essentially lifeless areas, such as regions in which there is no soil or where the soil is incapable of sustaining life.
What is secondary succession?It is a type of ecological succession in which plants and animals recolonize a habitat after a major disturbance such as a devastating flood, wildfire, landslide, lava flow, flood or human activity.
To know more about ecological succession here
https://brainly.com/question/12325701
#SPJ2
the first step in mitosis is the separateion of each pair of chromosomes true or false?
Answer:
true
Explanation:
Prophase is the first stage in mitosis, occurring after the conclusion of the G2 portion of interphase. During prophase, the parent cell chromosomes which were duplicated during S phase condense and become thousands of times more compact than they were during interphase.
How many moles of potassium sulfate are present in a sample that weighs 45.8g?
I do not understand how to solve this please help
Answer:
0.263 mol
Explanation:
K2SO4 - potassium sulfate
Molar mass (K2SO4) = 2*39.0983 + 32.065 + 4*15.9994 =
= 174.2592≈174.26 g/mol
45.8 g * 1 mol/174.26 g = 0.263 mol
What is the electrostatic potential energy (Eel) of the ionic bond between a Ca2+ ion and a S2– ion in joules? Before you do the calculation, predict whether the result you get will be less than (more negative) or greater than (less negative) than the Eel value for KCl. The ionic radii of Ca2+ and of S2– are 100 pm and 184 pm, respectively.
Answer: the electrostatic potential energy is -3.26 × 10⁻¹⁸ J
Explanation:
Given the data in the question;
I think the value of electrostatic potential energy of calcium sulfide CaS formed will be less(more negative) than KCl because the Ca2+ and S2- ions has more charge that is +2 and -2 respectively when compared to Kcl which has +1 and -1 charge.so it will be more negative.
radius = r[tex]_{ca+2}[/tex] + r[tex]_{s-2}[/tex] = 100 + 184 = 284 pm = 2.84 × 10⁻¹⁰ m
we know that; k = 2.31 × 10⁻²⁸ J
q1 = 2 ( charge on Ca⁺² )
q2 = -2( charge on S⁻²)
so
Ep = k × q1q2/r
so we substitute
Ep = 2.31 × 10⁻²⁸ × (+2×-2) / 2.84 × 10⁻¹⁰
Ep = (2.31 × 10⁻²⁸ × -4) / 2.84 × 10⁻¹⁰
Ep = -9.24 × 10⁻²⁸ / 2.84 × 10⁻¹⁰
Ep = -3.26 × 10⁻¹⁸ J
Therefore, the electrostatic potential energy is -3.26 × 10⁻¹⁸ J
Based on the data provided, the electrostatic potential energy is -3.26 × 10⁻¹⁸ J
What is electrostatic potential energy?The electrostatic potential energy is the work done in moving the charge from infinity to that point against the electric field.
The electrostatic potential energy between any two charges q1, q2 separated by distance r is derived from Coulomb’s law and mathematically given as:
E = k × [q1q2/r2]where
k is a constant = 2.31 × 10⁻²⁸ Jq1 and q2 are the chargesr is the distance of separationFrom the data provided:
ionic radii of Ca2+ r1 = 100 pm
ionic radii of S2– = 184 pm.
Chargeon Ca2+ = +2
Charge on S2_ = -2
From the data above, it most likely that the value of electrostatic potential energy of calcium sulfide CaS formed will be less(more negative) than KCl because the Ca2+ and S2- ions has a greater charge of +2 and -2 respectively compared to Kcl which has +1 and -1 charge.
Calculating the electrostatic potential energy, Ep:
radius = r1 + r2 = 100 + 184 = 284 pm
r = 2.84 × 10⁻¹⁰ m
k = 2.31 × 10⁻²⁸ J
q1 = 2 ( charge on Ca⁺² )
q2 = -2( charge on S⁻²)
Then:
Ep = k × q1q2/r
Substituting the values above in the equation:
Ep = 2.31 × 10⁻²⁸ × (+2 ×-2) / 2.84 × 10⁻¹⁰
Ep = (2.31 × 10⁻²⁸ × -4) / 2.84 × 10⁻¹⁰
Ep = -9.24 × 10⁻²⁸ / 2.84 × 10⁻¹⁰
Ep = -3.26 × 10⁻¹⁸ J
Therefore, the electrostatic potential energy is -3.26 × 10⁻¹⁸ J.
Learn more about electrostatic potential energy at: https://brainly.com/question/24648428
A liquid is a substance ______
Please help me I need this really quick
Answer:
The answer is (a)
.
.
......................................................................
If a sample contains 70.0 % of the R enantiomer and 30.0 % of the S enantiomer, what is the enantiomeric excess of the mixture?
Answer:
the enantiomeric excess of the mixture is 40%
Explanation:
The computation of the enantiomeric excess of the mixture is shown below:
As we know that
[tex]= |\frac{R - S}{R + S} |\times 100\\\\= |\frac{70 - 30}{70 + 30}| \times 100\\\\= 40\%[/tex]
Hence, the enantiomeric excess of the mixture is 40%
Learning Task 4: Think of two animals that reproduce sexually. In the first
box, draw an animal that fertilization occurs inside the body. In the second
box, draw an animal that exhibits external fertilization.
please help for me
In the first box, you should draw a chicken. In the second box, you should draw a cow or a horse.
I hope it helps you!!!! :D
[ pls mark me brainliest i need one more to rank up tysm if u do ]
Suggest a reason why it is desirable to use an excess of barium ion in the precipitation.
Answer:
Hello your question is poorly written hence i will give you a more general answer
answer : The reason why it is desirable to use an excess of barium ion in the precipitation is to form the compound needed,
Explanation:
Natural Precipitation occurs when condensed atmospheric water vapor falls due to the gravitational pull exerted on it by the clouds. precipitation can be in various forms like ; rain , ice pellets and snow . e.t.c
Hence the reason why it is desirable to use an excess of barium ion in the precipitation is to form the compound needed,
Also in order to form the precipitation, we will also add excess of barium ion which will help form the required precipitate and also filter out the mass of Sulphate.
59. Which one has 0 dipole moment?
a. H2O2 b. Co2 c. HF
d. HBr
Answer:
the answer to this question is A H202
Which one of these situations would have higher density water? Water with a lower salt content Water at the equator Water near where a river enters the ocean Lower temperature water
A higher density water will be obtained in lower temperature water.
What is density?Density is the fluid property that describes the amount of solutes that dissolves in a given volume of the fluid.
Density of a fluid is calculated by taking the ratio of mass to volume of the fluid.
[tex]\rho = \frac{m}{v}[/tex]
When the temperature of the water is low, more mass of the water is obtained while a high temperature evaporates the liquid.
Thus, a higher density water will be obtained in lower temperature water.
Learn more about density of water here: https://brainly.com/question/16794306
In two or more complete sentences describe all of the van der Waals forces that exist between molecules of hydrogen sulfide, H2S.
Suppose that the power
used by a light bulb in a circuit is 16 W, and the bulb has a resistance of 4 ohms.
Calculate the current (in amps) flowing through it.
In a reaction that produces carbon dioxide, the theoretical yield is 59 grams. During the experiment, the reaction actually produced 52.9 grams of carbon dioxide. Determine the percent yield.
Answer:
mole ratio, which is equivalent to a 1;1 mole ratio, to a gram ratio. This means that when the reaction consumes 84.03 g of carbon monoxide, it should theoretically produce 132.03 g of carbon dioxide. Use this gram ratio to calculate the theoretical yield for your reaction.
Explanation:
What is the molarity of a solution that contains 78.5 g of copper(II) chloride in 1.50 L of solution?
Answer:
0.389 M
Explanation:
From the question given above, the following data were obtained:
Mass of CuCl₂ = 78.5 g
Volume of solution = 1.50 L
Molarity of CuCl₂ =?
Next, we shall determine number of mole in 78.5 g of CuCl₂. This can be obtained as follow:
Molar mass of CuCl₂ = 63.5 + (35.5×2)
= 63.5 + 71
= 134.5 g/mol
Mass of CuCl₂ = 78.5 g
Number of mole of CuCl₂ =?
Mole = mass / Molar mass
Number of mole of CuCl₂ = 78.5 / 134.5
Number of mole of CuCl₂ = 0.584 mole
Finally, we shall determine the molarity of the solution. This can be obtained as follow:
Number of mole of CuCl₂ = 0.584 mole
Volume of solution = 1.50 L
Molarity of CuCl₂ =?
Molarity = mole / Volume
Molarity of CuCl₂ = 0.584 / 1.50
Molarity of CuCl₂ = 0.389 M
The molarity of a solution that contains 78.5 g of copper(II) chloride in 1.50 L of solution is 0.389M.
HOW TO CALCULATE MOLARITY?The molarity of a solution can be calculated
From the question given above, the following data were obtained:
Mass of CuCl₂ = 78.5 gVolume of solution = 1.50 LMolarity of CuCl₂ =?Next, we shall determine number of moles in 78.5g of CuCl₂. This can be obtained as follow:
Molar mass of CuCl₂ = 63.5 + (35.5×2)
= 63.5 + 71
= 134.5 g/mol
Mass of CuCl₂ = 78.5g
Number of mole of CuCl₂ = 78.5 / 134.5
Number of mole of CuCl₂ = 0.584 moles
The determine the molarity of the solution. This can be obtained as follow:
Number of moles of CuCl₂ = 0.584 molesVolume of solution = 1.50LMolarity of CuCl₂ =?Molarity = mole / Volume
Molarity of CuCl₂ = 0.584 / 1.50
Molarity of CuCl₂ = 0.389M
Therefore, molarity of a solution that contains 78.5 g of copper(II) chloride in 1.50 L of solution is 0.389M.
Learn more about molarity at: https://brainly.com/question/24650225
A hormone can have different effects in different species?
A. True
B. False
C. Cannot be decided
Answer:
true
Explanation:
it is because hormone determines various factors
When a chemical reaction is run in aqueous solution inside a calorimeter, the temperature change of the water (and Ccal) can be used to calculate the enthalpy change for the reaction. Here, we will study the reaction of hydrochloric acid with sodium hydroxide in the calorimeter from problem 3. Equal volumes (50.0 mL) of 1.00 M sodium hydroxide and 1.00 M hydrochloric acid are mixed.
HCl+NaOH→NaCl+H2O
1. What is the total change in enthalpy (in Joules) for the reaction?
2. Where initial temperature is 21.2 °C and final temperature is 28.0 °C. Ccal is 1234.28 j
Answer:
The total change in enthalpy for the reaction is - 81533.6 J/mol
Explanation:
Given the data in the question;
Reaction;
HCl + NaOH → NaCl + H₂O
Where initial temperature is 21.2 °C and final temperature is 28.0 °C. Ccal is 1234.28 J
Moles of NaOH = 50.mL × 1.00 M = 50.0 mmol = 0.0500 mol
Moles of HCl = 50.mL × 1.00 M = 50.0 mmol = 0.0500 mol
so, 0.0500 moles of H₂O produced
Volume of solution = 50.mL + 50.mL = 100.0 mL
Mass of solution m = volume × density = 100.0mL × 1.0 g/mL = 100 g
now ,
Heat energy of Solution q= (mass × specific heat capacity × temp Δ) + Cal
we know that; The specific heat of water(H₂O) is 4.18 J/g°C.
so we substitute
q_soln = (100g × 4.18 × ( 28.0 °C - 21.2 °C) ) + 1234.28
q_soln = 2842.4 + 1234.28
q_soln = 4076.68 J
Enthalpy change for the neutralization is ΔH[tex]_{neutralization}[/tex]
ΔH[tex]_{neutralization}[/tex] = -q_soln / mole of water produced
so we substitute
ΔH[tex]_{neutralization}[/tex] = -( 4076.68 J ) / 0.0500 mol
ΔH[tex]_{neutralization}[/tex] = - 81533.6 J/mol
Therefore, the total change in enthalpy for the reaction is - 81533.6 J/mol
Can youguys helpplease its for marks and is due tommorow.
Explanation:
i believe this is right. my bad if its not
Many homes that are not
connected to public sanitary
sewers might dispose of
sewage using a(n)
Answer:
pump that is the answer hope its right
