Inorganic Chemistry Answers

determine the mass of iron in (500Kg) of hematite (Fe2O3) if the percent of iron is 74%

Question 1:

A compound A reacts according to the following hypothetical equation and has a molecular weight of 48.36 g/mol.

3 A (s) +B (aq) ––> 2 C (aq) ∆H° = ?

A sample of A, weighing 0.152 g reacts in a flask containing 250.00 g of water and the water temperature increases from 24.85 °C to a temperature of 26.26 °C. Calculate ∆H° for the reaction as written in the equation.

Answer: -1408 kJ

Question 2:

For which of the following reactions is ∆H° = ∆H°f, the heat of formation?
i. C (s) + 2 F2(g) ––> CF4 (g) ∆H° = – 221.0 kJ
ii. H(g) + Br (g) ––> HBr (g) ∆H° = –366.2 kJ
iii. 2 C(s) + H2(g) + 3 Cl2(g) ––> 2 CHCl3 (g) ∆H° = –268.2

Could you also explain exactly what Delta H means.

a 25.0 mL sample of sodium sulfate was analyzed by adding an excess of barium chloride to produce barium sulfate crystals

Na2SO4(aq) + BaCl2(aq) -> 2NaCl(aq) + BaSO4(s)

If 5.719g of BaSO4 was obtained what was the molarity of the original Na2SO4?

7.004x10^26 molecules of CHCl3

In a titration of 20.00 mL H3PO4, 12.75 mL of 0.350 M NaOH were used. a)

Find the concentration of the acid in this experiment. b) The base solution was

not standardized. How will that affect the results? How would you standardize

such a solution?

A sample of gas is heated from -15.0 0C to 28.5 0C. What was its original

volume if the volume at 18.5 0C is 2.65 liters?

calculate the molarity of a 750.0 mL solution prepared by dissolving 65.00 g of zinc acetate into water

How much CuCl2 is needed to prepare 325g of 1.00%(w/w) solution?

What is the equations for the reactions occurring at the electrodes during electrolysis of the following solutions:
a) nickel sulfate with nickel electrodes
b) silver nitrate with silver electrodes
c) copper chloride with copper electrodes