General Chemistry Answers

Complete the equation for the dissociation of the electrolyte KOH(aq)

. Omit water from the equation because it is understood to be present.

A household cleaner contains 4.25 g of ammonia in 0.50 L of solution. There are 17.01 g in 1 mol of ammonia. What is the concentration of ammonia in mol/L?

1. A piece of zinc at 20.0∘C that weighs 60.0 g is dropped into 200.0 g of water at 100.0∘C. The specific heat of zinc is 0.389J/g∘C, and that of water near 100.0∘C is 4.22 J/g∘C. Calculate the final temperature reached by the piece of zinc and water.
2. When a 4.25-g sample of solid ammonium nitrate (NH4NO3) dissolves in 60.25 g of water in a coffee-cup calorimeter, the temperature drops from 22.55∘C to 16.0∘C. How much heat was transferred in the process?
3. A 2.200-g sample of quinone (C6H4O2) is burned in a bomb calorimeter whose total heat capacity is 7.857 kJ/∘C. The temperature of the calorimeter increases from 23.44∘C to 30.57∘C. What is the heat of combustion per gram of quinone? 
4. Under constant-volume conditions, the heat of combustion of glucose (C6H6O6) is 15.57 kJ/g. A 3.500-g sample of glucose is burned in a bomb calorimeter. The temperature of the calorimeter increased from 20.94∘C to 24.72∘C. What is the total heat capacity of the calorimeter?

Which functional group is present in the catechol?

Catechol

1. Hydroxyl
2. Phenol
3. Ester
4. Carbonyl
5. Carboxyl

Choose the answer that is written with the correct humber of significant figures. 

42.7 cm x 0.83 cm = 35.441 cm²

  35.4 cm²

  36 cm²

  35 cm²

  35.44 cm²

Ammonium hydrogen sulfide decomposes according to the following reaction, for which Kp 5 0.11 at 2508C:NH4HS(s) BA H2S(g) 1 NH3(g)If 55.0 g of NH4HS(s) is placed in a sealed 5.0-L container, what is the partial pressure of NH3(g) at equilibrium?

Convert 0.85 ppm of NO2 to ug/m3 at 210 K and 99.0 kPa pressure.Hint: Please apply temperature and pressure corrections and then make unit conversion.

 Note:

1 mole of a compound is equivalent to its molecular mass

1 mole of a compound is equal to 6.02x10^23 molecules

The percentage is a direct equivalent to grams

Answers should be in 3 significant figures

No need to include the units and the compound in the answers

1. A 60.00 g sample of tetraethyllead, a gasoline additive, is found to contain 38.43 g lead, 17.83 g carbon, and 3.74 g hydrogen. Find its empirical formula. 
2. A 170.00 g sample of an unidentified compound contains 29.84 g sodium, 67.49 g chromium, and 72.67 g oxygen. Find the empirical formula.  
3. Determine the molecular formula of the compound with an empirical formula of CH and a formula mass of 78.110 u

Note:

1 mole of a compound is equivalent to its molecular mass

1 mole of a compound is equal to 6.02x10^23 molecules

The percentage is a direct equivalent to grams

Answers should be in 3 significant figures

No need to include the units and the compound in the answers

1. A compound is found to contain 63.52 % iron and 36.48% sulfur. Find its empirical formula. 
2.   A compound is found to contain 26.56% potassium, 35.41% chromium, and the remainder oxygen. Find its empirical formula.  

Calculate the mass of Al

produced in 1.00 hr by the

electrolysis of molten AlCl3

if

the electrical current is 10.0 A