Chemistry Answers

in a laboratory,1.55g of organic compound containing C, H, and O is combusted for analysis combustion resulted in 1.45g of carbon II oxide and 0.890g of steam. what is the empirical formular of the organic compound

Determine the number of atoms in 1.75 mol of Al.

Methylhydrazine (N2H3CH3) is a common liquid propellant used in rocket fuels. Look for the standard molar enthalpies of formation of the reactants and products. Calculate the ∆Ho for the reaction.

(4)N2H3CH3 (l) + (5)N2O4 (l) ---> (12)H2O (g) + (9)N2 (g) + (4)CO2 (g)

What is the average kinetic energy (in kJ mol^-1) of a hypothetical gas with molecular weight 12.8 g mol^-1 at a temperature of 24.7 °C? Do not try to identify the gas.

The Haber process is used to synthesize ammonia (NH₃) on a large scale by the reaction of nitrogen gas with hydrogen gas as follows:

N_2 (g)  + 3 H_2 (g)  → 2 NH_3 (g)

Consider a reaction between a 6.79 L flask containing nitrogen gas and a 14 L flask of hydrogen gas. Both gases have a temperature of 281 K and the pressures inside both flasks is 0.88 bar.

What mass of ammonia (in g) would you expect to be produced at temperature 281 K and a pressure of 0.88 bar? 

A sample of hydrogen (H₂) gas was collected over water at 60°C.

If the total volume of gas collected was 60.5 mL and the atmospheric pressure was 1.1 bar, what mass (in g) of hydrogen gas was collected above the water?

The vapour pressure of water at 60°C is 150 torr.

Answer:

A flask contains a mixture of two gases: NO₂ and Ne. If the flask contains 0.768 mol of NO₂ and 14.8 g of Ne at a total pressure of 1.17 bar, what is the partial pressure of Ne in the flask (in bar?)

TIP: You don't need the volume of the flask nor the temperature to solve this problem.

What is the pressure (in bar) at which a gas of molar mass 30 g/mol at temperature 24.3 °C has a density of 3.66 g/L?

NOTE: The given molar mass may not correspond to an actual gas. Do not try to identify the gas.

Acetone and ethanol have boiling points of 56 °C and 78 °C, respectively. Which do expect to have a higher

vapor pressure at 25°C? Explain.

Automotive antifreeze consists of ethylene glycol, CH

2

(OH)CH

2

(OH), a nonvolatile nonelectrolyte. Calculate the

boiling point and freezing point of a 25.0 wt% solution of ethylene glycol in water.