Question

1. Nitrogen gas and sodium liquid are produced by the decomposition of sodium azide NaN3 (s). what volume of nitrogen gas, measured at 25 C and 0.980 atm, is produced by the decomposition of 62.5 g of sodium azide?

2. A gas sample in a container with a volume “V” at a temperature “T” with a total number of moles “n”, has 76.8 mole percent N2 (g), 20.1 mole percent O2 (g), and 3.1 mole percent CO2 (g). if the ratio nRT/V is equal to 1.002, what are the partial pressures of the three gases?

3. A liquid hydrocarbon (Cx Hy) is found to be 16.37% H by mass. A 1.158-g vaporized sample of the hydrocarbon has a 358 mL volume at 71.0 C and 749 mmHg. what is the molecular formula for this hydrocarbon?

4. A 1.00 g Sample of C7H603 (s), us completely burned in a bomb calorimeter assembly by a temperature increase of 5.80 C is noted. when the calorimeter absorbs 9.37 Kj of heat, its temperature increases by 2.48 C.

-what is the heat capicity of the calorimeter?

- what is the amount of heat given off when 1 mole of C7H6O3 (s) burned? (use qcal= C cal x delta T cal)

5. given that

N2 05 + H2O (l) ---> 2HNO3 (l) delta H = -73.7 KJ

2H2 (g) + 02 (G) ---> 2H2O (L) delta H = -571. 6 KJ

N2 (g) + 3O2 (g) + H2 (g) ---> 2HNO3 (L) delta H = -348.2 KJ

Calculate delta H final (standard enthalpy of formation) if dinitrogen pentoxide gas.

6. A gass effuse 1.55 times fatser than propane C3H8 (g) at the same temperature and pressure.

- is the gas heavier or lighter than propane?

- what is he molar mass of this gas?

Answer 1

This may be your first time to post on Jishka. It is best to make only one question per post. Posts with more than that get too long to answer. Here is help with the first one.
1. Write the equation and balance it.
2. Convert 62.5 g NaN3 to moles. moles = grams/molar mass
3. Using the coefficients in the balanced equation, convert moles NaN3 to moles of the product, N2.
4. Use PV = nRT, substitute n for number of moles and P and T conditions in the problem calculate volume.

Answer 2

I got # 1
Pleas help with the 2nd

A gas sample in a container with a volume “V” at a temperature “T” with a total number of moles “n”, has 76.8 mole percent N2 (g), 20.1 mole percent O2 (g), and 3.1 mole percent CO2 (g). if the ratio nRT/V is equal to 1.002, what are the partial pressures of the three gases?

Answer 3

The mole fractions are:
0.768 for N2
0.201 for O2
0.031 for CO2

PV = nRT and rearranged it is
P = nRT/V which the problem tells us 1.002.

PN2 = mole fraction N2 * 1.002 (in atmospheres.
PO2 = mole fraction O2*1.002 atm
PCO2 = mole fraction CO2*1.002 atm.

Answer 4

thank u
so it is

n2 ---> (76.8/100)x (1.002)!!!

ok...great can u help me with 3, 4, and 5 please if u be so generous

Answer 5

do you have the answers to 3, 4, and 5?