General Chemistry Answers

2) Calculate the Δ

Δ

H value heat for the following reaction: Ag2S(s)  + 2 HCl(g) -->  2 AgCl(s) + H2S(g) Δ

Δ

H = ? kJ/mol Solve by writing formation equations for each reactant and product and using the Δ

Δ

H values for each.

A 112 kg man stands 551 m from a building with a mass of 25,500 kg. What was the force of gravity experienced by the man?

A buffer solution is prepared via adding solution A (Sodium

dihydrogen phosphate 27.6 gm up to 1000mL distilled water) and

solution B (Disodium hydrogen phosphate 5.362gm up to 100mL

distilled water). During preparation, 1000 mL buffer is prepared

via adding 80mL of solution B to 920mL of solution A. Show a

theoretical approach to calculate the pH of the buffer solution.

____ NaBr + ____ Ca(OH)2  ___ CaBr2 + ____ NaOH

Combustion of unknown compound yielded 10.36 g of water, 36.98 g of carbon dioxide, and 8.058 g of nitrogen. The complete combustion of the compound needed 36.84 g of oxygen gas. Find the empirical formula of the compound.

Balance the combustion equation.

1. In the course of combustion analysis of an unknown compound, 13.454 g of carbon dioxide, 5.504 g of water and 7.134 g of nitrogen were measured. The complete combustion of the compound needed 6.523 g of oxygen gas. What is the empirical formula of the unknown compound?

1a. Balance the combustion reaction

is ZnBr_{2 binary}

1. A one-liter buffer solution was made of ammonia (0.33 M)-

ammonium chloride (0.33 M) at equilibrium. A student was asked

to add 0.05 mol HCl to that solution. However, he mistakenly

added 0.07 mol NaOH to that solution. Assume no change in the

volume of the buffer.

(a) What type of buffer solution it was. Provide its mechanism.

(b) Calculate the change of pH of the buffer after the mistake of the

student

(c) What would be the change of pH if the student adds 1000 mL

water to that buffer solution?

A buffer solution is prepared via adding solution A (Sodium dihydrogen phosphate 27.6 gm up to 1000mL distilled water) and solution B (Disodium hydrogen phosphate 5.362gm up to 100mL distilled water). During preparation, 1000 mL buffer is prepared via adding 80mL of solution B to 920mL of solution A. Show a theoretical approach to calculate the pH of the buffer solution.

What is the pH when 20 ml 0.1 M HCl is added to 100 ml 0.1M NaCN?