Explanation:
number of moles = mass /relative molecular mass
n = 25,92/mr(N2)
n=25,92/14×2
n=25,92/28
n=0.93moles
How many mL of 14.5M lithium carbonate solution must be used to deliver 4.20 g of lithium ion
Answer:
. 750 M
Explanation:
If you have 0.36mol C that reacts with excess CuO, how many atoms do you have of Cu?
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.
4. Consider the following reaction:
A student performs a neutralization reaction at 298 K according to the following reaction:
NaHCO3 (8) + HCH,O2 (aq) → H20 (1) + CO2 (g) + NaC,H3O2 (aq)
The student adds 1.85 g of solid NaHCO3 into a flask containing 75.0 mL of 0.90 M HCH:02. The student
observes the formation of gas bubbles and also that the flask gets cooler to the touch as the reaction proceeds.
Considering all of the students observations that the student made, is the reaction thermodynamically favorable
at all temperatures, no temperatures, high temperatures or low temperatures. Justify (explain) your selection in
terms of AG
Answer:
High temperatures
Explanation:
NaHCO₃ (8) + HCH,O₂ (aq) → H₂O (l) + CO₂ (g) + NaC,H₃O₂ (aq)
As the flask gets cooler to the touch as the reaction proceeds, the reaction is endothermic. This means that ΔH is positive (ΔH>0).
As a gas is formed (bubbles are formed), ΔS is positive (ΔS>0).
In terms of ΔG:
ΔG = ΔH - TΔSIn order for the reaction to be thermodynamically favorable, ΔH has to be negative, thus:
The reaction is favorable if TΔS > ΔH.The greater the temperature, the easier it would be for TΔS to be greater than ΔH.
If 25.00 mL of 6.00 M HCl is transferred by pipet into a volumetric flask and diluted to 5.00 L, what is the molarity of the diluted HCl?
Answer:
0.03 M
Explanation:
The computation of the molarity of the diluted HCI is given below:
As we know that
(M1) × (V1) = (M2) × (V2)
Now
(M2) = {(M1) × (V1)} ÷ (V2)
or
Molarity of the diluted HCl,(M2) is
= {6 × 25} ÷ 5000
= 0.03 M
Which type of solution below has a cloudy appearance? (Choose all that apply)
a. Colloids
b. Suspensions
c. Solutions
d. Alloys
The type of solutions which are appearing cloudy are called colloids. Therefore, option a is correct.
What are colloids ?Colloids are mixtures in which particles of one substance are evenly dispersed throughout another substance, creating a stable mixture. The particles in a colloid are larger than those found in a solution, but smaller than those found in a suspension.
Colloids can be found in various states of matter, including solid, liquid, and gas, and they can be formed from a wide range of substances, such as polymers, metals, and biological molecules.
One important characteristic of colloids is their ability to scatter light. This phenomenon, known as the Tyndall effect, occurs when light passes through a colloid and is reflected by the particles, causing the mixture to appear cloudy or hazy.
Colloids also exhibit unique properties related to their size and shape, such as viscosity, surface tension, and Brownian motion. They appear cloudy in nature.
Find more on colloids:
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Explain the 3 steps required to determine the molecular formula.
Answer:
The steps involved in determining a Molecular Formula are: Find the mass of the empirical formula. Divide the molecular mass by the mass of the empirical formula. Multiply each subscript in the empirical formula by the answer.
Explanation:
What is the vapor pressure of a solution in which the mole fraction of the solute is 0.200 and the vapor pressure of the pure solvent is 100.0 torr? (Assume a single nonvolatile, nonelectrolyte solute).
a. 0 torr
b. 80.0 torr
c. 100.0 torr
d. 120.0 torr
e. 20.0 torr
Answer: The vapor pressure of a solution in which the mole fraction of the solute is 0.200 is 80.0 torr
Explanation:
As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.
The formula for relative lowering of vapor pressure will be,
[tex]\frac{p^o-p_s}{p^o}=i\times x_2[/tex]
where,
[tex]p^0[/tex]= vapor pressure of pure solvent = 100.0 torr
[tex]p_s[/tex] = vapor pressure of solution = ?
i = Van'T Hoff factor = 1 for nonvolatile, nonelectrolyte solute
[tex]x_2[/tex] = mole fraction of solute = 0.200
[tex]\frac{100.0-p_s}{100.0}=1\times 0.200[/tex]
[tex]p_s=80.0torr[/tex]
The vapor pressure of a solution in which the mole fraction of the solute is 0.200 is 80.0 torr
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
A car travels 75 mi/hr. How many hours will it take to travel 837 km? (Pick the answer closest to the correct answer,
1.61 km=1 mile)
Answer:
6.9 hours
Explanation:
In order to solve this problem we'll convert 837 km to miles (another option would be to convert 75 mi/hr to km/hr). To make said conversion we'll use the given conversion factor:
837 km * [tex]\frac{1mi}{1.61km}[/tex] = 519.88 miFinally we calculate the time required to travel said distance at a constant speed of 75 mi/hr:
519.88 mi ÷ 75 mi/hr = 6.9 hrThe amount of time it would take to travel 837 km is equal to 7 hours.
Given the following data:
Speed = 75 mi/hr.Distance = 837 km.To determine the amount of time it would take to travel 837 km:
How to calculate time.First of all, we would convert the value of the distance in kilometers to miles as follows:
Conversion:
1.61 km = 1 mile
837 km = X mile.
Cross-multiplying, we have:
[tex]X=\frac{837}{1.61}[/tex]
X = 519.88 miles.
Mathematically, time is given by this formula:
[tex]Time = \frac{distance}{speed}[/tex]
Substituting the given parameters into the formula, we have;
[tex]Time = \frac{519.88}{75}[/tex]
Time = 6.93 ≈ 7 hours.
Read more on time here: https://brainly.com/question/12199398
List a couple general characteristics of primary consumers and list a few examples.
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.
Question 6: Describe an experiment for determining the position in the reactivity series for
copper, iron and magnesium. Include safety measures and the equipment you would use (5
Marks) *
(5 Points)
Enter your answer
BI
(hp)
Answer: BI
because of rection progress
Explanation:
5. Why is picric acid and tannic acid used in the treatment of burns?
Some instruments differentiate individual quanta of electromagnetic radiation based on their energies. assume such an instrument has been adjusted to detect quanta that have 3.50× 10–16 j of energy. what is the wavelength of the detected radiation? give your answer in nanometers.
Answer:
5.68×10¯¹⁰ m
Explanation:
From the question given above, the following data were obtained:
Energy (E) = 3.50×10¯¹⁶ J
Wavelength (λ) =?
Energy (E) and wavelength (λ) are related according to the following formula:
E = hv/λ
Where
E => is the energy
h => is the Planck's constant
v => is the velocity of electromagnetic radiation
λ => is the wavelength of the radiation.
With the above formula, we can obtain the wavelength of the radiation as follow:
Energy (E) = 3.50×10¯¹⁶ J
Planck's constant (h) = 6.63×10¯³⁴ Js
Velocity (v) = 3×10⁸ m/s
Wavelength (λ) =?
E = hv/λ
3.50×10¯¹⁶ = 6.63×10¯³⁴ × 3×10⁸ / λ
3.50×10¯¹⁶ = 1.989×10¯²⁵/ λ
Cross multiply
3.50×10¯¹⁶ × λ = 1.989×10¯²⁵
Divide both side by 3.50×10¯¹⁶
λ = 1.989×10¯²⁵ / 3.50×10¯¹⁶
λ = 5.68×10¯¹⁰ m
Thus, the wavelength of the radiation is
5.68×10¯¹⁰ m
Determine the number of atoms in 4.60 g gold.
Answer:
N(Au) = 1,20 × 10²²
Explanation:
1) n(Au) = m ÷ M = 4.60 g ÷ 197 g/mol = 0,02 mol
2) N(Au) = n(Au) × N(a) = 0,02 × 6.02*10²³ = 1,20 × 10²²
The point where ground water reaches the surface and pours out is called a summer? true or false
Answer:
False
Explanation:
Groundwater and surface water have a relationship.
Groundwater is the water that is contained in a subsurface layer of an underlying soil/rock whereas surface water is that found in a lake, river or some other surface cavities.
However, when groundwater is discharged to surface water bodies, it is said to be surface water. Thus the statement asked is false.
Which of the following devices function on redox reaction ... Drycell, car battery and electric generator
Answer:
Drycell and car battery
Explanation:
Is it only one answer because I think both of these are redox reactions.
From previous experiments, this chemical reaction is known to absorb of energy. The position of the piston is monitored, and it is determined from this data that the system does of work on the piston during the reaction. Is the reaction exothermic or endothermic? exothermic endothermic Does the temperature of the water bath go up or down? up
Hello. Your question is missing data, which makes it difficult to answer it with exactness, but I will try to help you in the best possible way.
If the reaction absorbs energy it means that the reaction is endothermic. This is because endortemic reactions are those that absorb energy from the environment, as opposed to exothermic reactions that release energy into the environment.
In that case, if the reaction is absorbing energy, it is appropriate for the water bath temperature to drop.
What is the mole percent of ethanol (C2H5OH), which consists of 71.0 g of ethanol for every 18.6 g of water present?A. 87.7%.B. 22.1%.C. 26.5%.D. 73.5%.E. 71.0%.
Answer:
Mole percent of Ethanol = 0.5986 * 100 = 59.86%
Explanation:
Mole percent is the percentage of the total moles that is of a particular component.
We have to covert the ethanol and water to moles. This is given by the equation;
Number of moles = Mass / Molar mass
Ethanol;
Number of moles = 71 / 46.07 = 1.5411 mol
Water;
Number of moles = 18.6 / 18 = 1.033 mol
Total mol = 1.5411 mol + 1.033 mol = 2.5741 mol
Mole percent of Ethanol = Number of moles /(Ethanol) / Total moles * 100
Mole percent of Ethanol = 1.5411 mol / 2.5741 mol * 100
Mole percent of Ethanol = 0.5986 * 100 = 59.86%
Which of the following is true regarding the difference between velocity and speed? *
Velocity can be negative whereas speed can only be positive.
Velocity includes a direction whereas speed is a numerical value only.
Velocity relies on displacement whereas speed relies on distance.
All of the above.
Answer:
All of the aboveSpeed is the time rate at which an object is moving along a path, while velocity is the rate and direction of an object's movement. Put another way, speed is a scalar value, while velocity is a vector.
Explanation:
Hope it is helpful.....
The theory of evolution states
Answer:
the theory of evolution states that all living things which exist today, and many more that are now extinct, evolved from simple life forms which first developed 3 billion years ago.
Explanation:
Describe what an Ionic Substance is....
Answer:
Ionic Substance is....
Explanation:
In chemistry, an ionic compound is a chemical compound composed of ions held together by electrostatic forces termed ionic bonding. The compound is neutral overall, but consists of positively charged ions called cations and negatively charged ions called anions.
How many mL of 14.5M lithium carbonate solution must be used to deliver 4.20 g of lithium ion
Answer:
10.3 g Li) / (6.9410 g Li/mol) x (1 mol Li3PO4 / 3 mol Li) / (0.750 mol/L Li3PO4) = 0.6595 L = 660. mL
Explanation:
A 150.0mL sample of an aqueous solution at 25C contains 15.2mg of an unknown nonelectrolyte compound. If the solution has an osmotic pressure of 8.44 torr, what is the molar mass of the unknown compound?
Answer:
MM = 225.11 g/mol
Explanation:
In this case, let's analyze the data.
We have a 15.2 mg of an unknown electrolyte in 150 mL of solution. The osmotic pressure is 8.44 Torr, and we want the molecular mass of the unknown.
The osmotic pressure can be calculated using the following expression:
π = CRT (1)
π: osmotic pressure (8.44 Torr * 1 atm / 760 Torr = 0.011 atm)
C: Concentration of the unknown in the solution
R: universal constant of gases (0.082 L atm / K mol)
T: temperature in Kelvin (25 + 273 = 298 K)
From this expression, we can either solve for C, and then use another expression to calculate the molecular mass, or we can just replace the expressions in the above formula, to get the direct molecular mass. In this case, we'll follow the second method.
Concentration or molarity of a substance can be calculated using:
C = moles / V (2)
And moles can be calculated using this expression:
moles = m / MM (3)
Replacing (3) in (2), and then in (1) we have:
C = m / MM * V
π = m * RT / MM * V (4)
and now, we can solve for MM:
MM = mRT / π V (5)
Now, we just need to replace the given data into the above expression to get the value of the molecular mass:
MM = (15.2 / 1000) * 0.082 * 298 / 0.011 * 0.150
MM = 225.11 g/molHope this helps
What is the freezing point (in degrees Celcius) of 4.14 kg of water if it contains 235.1 g of butanol, C 4 H 9 O H
Answer:
Explanation:
Molal freezing point depression constant of butanol Kf = 8.37⁰C /m
ΔTf = Kf x m , m is no of moles of solute per kg of solvent .
mol weight of butanol = 70 g
235.1 g of butanol = 235.1 / 70 = 3.3585 moles
3.3585 moles of butanol dissolved in 4.14 kg of water .
ΔTf = 8.37 x 3.3585 / 4.14
= 6.79⁰C
Depression in freezing point = 6.79
freezing point of solution = - 6.79⁰C .
2KMnO4 + 16HCl -> 5Cl2 + 2KCl + 2MnCl2 + 8H2O If 6.0 moles of KCl are produced, how many moles of HCl were reacted?
Answer:
Explanation:
You just use the balance mole numbers from the equation.
moles HCl needed/16 from the balanced equation ==> 6KCl/2 from equation
x / 16 = 6/2 Multiply both sides by 16
x = 16 * 6 / 2
x = 48
You need 48 mols of HCl
What do chemists study?
A. The properties of matter and how matter changes
B. How matter and energy interact
C. Mathematical principles
D. Living things
SUBMIT
A. The properties of matter and how matter changes.
Answer: A. the properties of matter and how matter changes
Explanation:
just got it right
Which product of photosynthesis is the food?
Oxygen
Carbon Dioxide
Water
Glucose
Answer:
Oxygen
Explanation:
In photosynthesis, solar energy is harvested and converted to chemical energy in the form of glucose using water and carbon dioxide. Oxygen is released as a byproduct.
Answer:
the answer is a) oxygen
Explanation:
when plants are performing photosynthesis they take in carbon dioxide given out by humans and animals which is the balance of nature and give out oxygen. in this process sunlight and chlorophyll is also involved!!!!
I hope I cleared your doubt :)
When riding a roller coaster, you go up and down many hills. As you get to the top of a roller coaster, what energy change is taking place?
A. potential energy is changed into kinetic energy
B. kinetic energy is changed into potential energy
C. chemical energy is changed into heat energy
D. heat energy is changed into chemical energy
Answer:
A.
Explanation:
The potential energy of the roller coaster increases as the coaster goes up a hill and can be converted to kinetic energy.
