General Chemistry Answers

When 10.0 mL 0.100 M NaOH and 5.00 mL 0.200 M HCl were mixed in a coffee-cup calorimeter (heat capacity = 46.5 J °C-1), the temperature increased by 1.20°C. Determine the change in enthalpy of the reaction (in kJ mol-1)

Hydrogen gas can be collected from the reaction of a metal element with a strong acid as

shown. When a 500.0 mg iron metal sample was soaked in 50.00 mL 0.500 M HNO3, 16.00 mg H2 was collected. How efficient is this process?

2Fe + 6HNO₃ → 2Fe(NO₃)₃ + 3H₂

What is the change in internal energy of a system if the surroundings absorb 145 J of heat from the system while doing 98 J of work on the system?

1. Consider a 1.245 g sample of glucose (C₆H₁₂O₆). Calculate the following:
2. Mole of glucose in the sample;
3. Moles of carbon in one (1) mole of glucose;
4. Moles and mass of carbon in the sample; and
5. Glucose molecules in the sample.

What is the change in internal energy of a system if the surroundings absorb 145 J of heat from the system while doing 98 J of work on the system?

The process of producing sulfur dioxide from its elements (i.e. S2(g) and O2(g)) is reported to be 62% efficient. How much sulfur (in g) must react so that 1.00 g SO2 will be collected?

S2(g) + 2O2(g) → 2SO2(g)

Hydrogen gas can be collected from the reaction of a metal element with a strong acid as shown. When a 500.0 mg iron metal sample was soaked in 50.00 mL 0.500 M HNO3, 16.00 mg H2 was collected. How efficient is this process?

2Fe + 6HNO3 → 2Fe(NO3)3 + 3H2

When 10.0 mL 0.100 M NaOH and 5.00 mL 0.200 M HCl were mixed in a coffee-cup

calorimeter (heat capacity = 46.5 J °C-1), the temperature increased by 1.20°C. Determine the

change in enthalpy of the reaction (in kJ mol-1)

A mole of a newly discovered crystalline substance weighs 14.56 grams and displaces 2.3 ml of water. What is the density of the crystal? Find the atomic radius and density of each atom if it is a simple cubic cell? BCC? FCC? HCP?

Phosphoric acid (H3,PO4) is a key ingredient in soft drinks that gives it a

sharper flavor. One way to produce this acid is with the aid of mineral

fluoroapatite (Ca5(PO4)3F) following this reaction:

Ca5(PO4)3F + 5H2SO4 → 3H3PO4 + 5CaSO4 + HF

If 24.5 g Ca5(PO4)3F is mixed with 89.7 g H2SO4

, how much H3PO4 will form?