1. A 0.0250 g sample containing cyanide (26.02 g/mol) was dissolved in a given solvent. After addition of the AgNO3 (169.87 g/mol), a 0.0125 g of AgCN (133.89 g/mol) was obtained. What is the percent of cyanide in the sample?

- 9.72%

- 7.64%

- 1.91%

-19.5%

2. A 0.8870 g sample containing only NaCl (58.45 g/mol) and KCl (74.55 g/mol) was treated with AgNO3. The AgCl (143.32 g/mol) formed had a mass of 1.913 g. Calculate the mass of NaCl and KCl in the sample.

- NaCl = 0.4375 g and KCl = 0.4495 g

- NaCl = 0.4435 g and KCl = 0.4435 g

- NaCl = 0.3914 g and KCl = 0.4952 g

- NaCl = 0.2650 g and KCl = 0.6220 g

3. A 0.8870 g sample containing only NaCl and KCl was treated with AgNO3. The AgCl (143.32 g/mol) formed had a mass of 1.913 g. Calculate the mass of chloride (35.45 amu) in the sample.

- 0.473 g

- 1.913 g

- 1.2355 g

- 1.678 g