1. A 5.0 mL sample of hydrogen gas is collected at a pressure of 97.5 kPa when the temperature is 18°C. Calculate the volume this gas would occupy at STP in liters.

- Note: STP stands for Standard Temperature and Pressure, which means the temperature is 0°C and the pressure is 101.3 kPa = 1 atm.

2. Balance the following equation: _____ H$_2$ + _____ N$_2$ → _____ NH$_3$

A. What type of reaction is this?
Answer:

B. Are the number of moles conserved in the balanced equation? Justify your reasoning in complete sentences.
Answer:

C. How does the balanced equation support the law of conservation of mass, in grams? Justify your reasoning in complete sentences.
Answer: __

D. How many moles of ammonia (NH$_3$) can be produced from the reaction of 4.0 liters of hydrogen at 50.0°C and 1.2 atm of pressure with excess nitrogen?
Answer to 2D: _

3. Ammonium nitrite decomposes to give off nitrogen gas and liquid water. How many grams of ammonium nitrite must have reacted if 2.58 L of gas was collected over water in a gas collecting tube at 21.0°C and 97.8 kPa?

- Balanced equation: ___________________________________
Answer to 3: _

4. Will the volume of nitrogen (from the previous problem) increase, decrease, or remain the same if:

A. The experiment is done at a significantly higher temperature?
Answer:

B. The amount of ammonium nitrite was increased?
Answer:

C. The experiment was not collected over water?
Answer: __

5. A reaction of 900.0 mL of 3.00 M phosphoric acid (H$_3$PO$_4$) with 235 grams of iron (III) carbonate is given by the balanced equation:

\[ \text{Fe}_2(\text{CO}_3)_3 + 2\text{H}_3\text{PO}_4 \rightarrow 2\text{FePO}_4 + 3\text{H}_2\text{O} + 3\text{CO}_2 \]

a. Determine the limiting reactant. Show all work!
Answer to 4a: _

b. How many milliliters of carbon dioxide gas can be produced at 78°C at 45.5 psi pressure with 900.0 mL of 3.00 M phosphoric acid and 235 grams of iron (III) carbonate?
Answer to 4b: _

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Note: Standard pressures: 1 atm = 760 torr = 760 mmHg = 101.3 kPa = 101,300 Pa = 14.7 psi.

1. To find the volume of a gas at STP, we can use the ideal gas law, which is an equation that relates the pressure, volume, temperature and amount of a gas. The equation is:

PV = nRT

where P is the pressure, V is the volume, n is the number of moles, R is the gas constant and T is the temperature.

We can rearrange this equation to find V:

V = nRT/P

We need to make sure that we use consistent units for P, V, T and R. Since we are given P in kPa and T in °C, we can use R = 8.31 J/(K⋅mol) and convert T to K by adding 273.15.

We also need to find n, which is the number of moles of hydrogen gas. We can use the molar mass of hydrogen, which is 2.02 g/mol, to convert the given mass of 5.0 mL to moles. Since 1 mL of gas at STP has a mass of 0.0899 g, we have:

5.0 mL × 0.0899 g/mL ÷ 2.02 g/mol = 0.00222 mol

Now we can plug in the values into the equation for V:

V = (0.00222 mol)(8.31 J/(K⋅mol))(273.15 + 18) K / (97.5 kPa)

V = 0.00507 m^3

To convert m^3 to L, we multiply by 1000:

V = 5.07 L

Therefore, the volume of hydrogen gas at STP is about 5.07 L.

2. To balance the equation for the reaction of hydrogen and nitrogen to form ammonia, we need to make sure that the number of atoms of each element is equal on both sides of the equation. We can do this by adjusting the coefficients (the numbers in front of each compound) until they match.

One possible way to balance the equation is:

3H2 + N2 → 2NH3

A. This type of reaction is called a synthesis reaction or a combination reaction, because two or more substances combine to form a single product.

B. The number of moles are conserved in the balanced equation, because there is no change in the total number of molecules involved in the reaction. According to the balanced equation, three moles of hydrogen react with one mole of nitrogen to produce two moles of ammonia.

C. The balanced equation supports the law of conservation of mass, which states that mass cannot be created or destroyed in a chemical reaction. According to the balanced equation, the total mass of the reactants is equal to the total mass of the product, because each atom has a fixed mass and no atoms are lost or gained in the reaction.

D. To find how many moles of ammonia can be produced from 4.0 liters of hydrogen at 50°C and 1.2 atm of pressure with excess nitrogen, we need to use the ideal gas law again to find how many moles of hydrogen are present:

PV = nRT

n = PV/RT

n = (1.2 atm)(4.0 L) / ((0.082 L⋅atm)/(K⋅mol))(273 + 50) K)

n = 0.19 mol

Since we have excess nitrogen, hydrogen is the limiting reactant, meaning that it will be completely consumed in the reaction and determine how much ammonia can be produced.

According to the balanced equation, three moles of hydrogen produce two moles of ammonia, so we can use this ratio to find how many moles of ammonia are produced from 0.19 mol of hydrogen:

(2 mol NH3 / 3 mol H2) × 0.19 mol H2 = 0.13 mol NH3

Therefore, about 0.13 moles of ammonia can be produced from 4.0 liters of hydrogen at 50°C and 1.2 atm with excess nitrogen.