General Chemistry Answers

1. How many calories are in 4691 kJ? ( 1 cal = 4.18J)
2. How many Joules are there in 2001 calories? ( 1 cal = 4.18J)

A 516.7-mg sample containing a mixture of K2SO4 and (NH4)2SO4 was dissolved in water and treated with BaCl2, precipitating the SO4 2– as BaSO4. The resulting precipitate was isolated by filtration, rinsed free of impurities, and dried to constant weight, yielding 863.5 mg of BaSO4. What is the %w/w K2SO4 in the sample?

How many moles of H2SO4 are present in 1.63 liters of a 0.954 M solution?

 The atomic number of boron is 5. Boron exists as two isotopes boron-10 and boron-11. Use this information to explain why

A 38.63-mg sample of potassium ozonide, KO3, was heated to 70 °C for 1 h, undergoing a weight loss of 7.10 mg. Write a balanced chemical reaction describing this decomposition reaction. A 29.6-mg sample of impure KO3 experiences a 4.86-mg weight loss when treated under similar condition. What is the %w/w KO3 in the sample?

What is the term given to the opposite of catalyst?

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?