In the mixture of NO and CO2 (initially containing 4 mol of NO and 0.9 mol of CO2) reaction occurs according to the equation below.

NO+ CO2 = NO2 + CO

At equilibrium 0.1 mol of CO2 was present . What is the equilibrium constant, Kc at the temperature of this experiment?

Which one of the following affects the value of the solubility product Ksp of silver sulphide when it is precipitated by passing hydrogen sulphide into aqueous silver nitrate?

An acidified solution containing 0.1 M of zinc sulphate and 0.1 M of copper (II) sulphate is saturated with hydrogen sulphide at 15 ⁰C . The concentration of S^-2 in the solution is then 10 ^-35 M.

The solubility product of zinc sulphide at 15 ⁰C is 10 ^-24 M² and then copper (II) sulphide is

10 ^-40 M² .

Which statement describes what happens in the solution?

If the equilibrium is established by initially adding 0.10 mol each of A and B to a 1L container, then which of the following must be true once the mixture achieves equilibrium?

A + 2B = 2C K = 320

A reaction X + 2Y → 3Z is started with 1.0 M Z and no X or Y. To calculate the equilibrium concentrations of all species using an ICE table, which of the following would you enter in the Z column for the C row?

The addition of HCl does not suppress the dissociation of:

In which of the following the solubility of AgCl is minimum?

If 200 mL of 1x10^–7 M AgNO₃ is mixed with 200 mL of 1x10^–8 M NaI, what will occur? For AgI, Ksp = 8.3 x 10^–17 .

What is the specific heat capacity of a substance if 2.41x10⁴ J are needed to change the temperature of 105.0 g of it from 25.0ºC to 250.0ºC?

Given the following two reactions:

C_(s) + O_2(g) → CO₂(g) ∆H = -393.5 kJ

2Fe_(s) + 3/2 O2 _(g) → Fe₂O_3(s) ∆H = -824.2 kJ

Calculate the enthalpy change for 2Fe₂O_3(s) + 3C_(s) → 4Fe_(s) + 3CO_2(g)

Calculate the ∆H for the following reaction using the bond energies given below:

H-H (g) + I-I (g) → 2H-I (g)

Bond energies: H-H = 436 kJ/mol, I-I = 151 kJ/mol, H-I = 297 kJ/mol

Calculate the enthalpy change represented by X

The picture shows two completely identical mason jars. They're both filled with the same gas, only one of them has more in it (more molecules). What can you say about the pressures of both jars?

A measure of the amount of disorder or randomness in a system.

A compound X contains 50% Sulphur and 50% Oxygen by mass.

What is the empirical formula of compound X?

Vitamin C has the following structural formula

What is the empirical formula of vitamin C?

Which of the following statements about the mole are correct?

I. 12g of carbon contains one mole of atoms

II. 28g of nitrogen gas contains one mole of molecules

III. 1 dm³ of 1.0 mole/dm³ solution of sodium chloride contains one mole of chloride ions.

When sugar is fermented using yeast, the reaction below takes place.

C₁₂H₂₂O₁₁ + H₂O → 4C₂H₅OH + 4CO₂

What volume of carbon dioxide at R.T.P would be produced by the complete fermentation of 1000g of sugar?

(Molar mass of sugar is 342)

Which of the following statements concerning a solution labelled 0.1 mol/dm³ barium chloride, BaCl₂, are true?

I. It contains 0.1mol of barium ions in 1dm³.

II. It contains 0.1mol of chloride ions in 500cm³.

III. It contains 0.3mol of ions in 1dm³.

Silicon carbide, an abrasive, is made by the reaction of silicon dioxide with graphite.

SiO2 +3C→ SiC + 2CO

If 100 g of SiO2 and 100 g of C are reacted as far as possible, which one of the following

statements will be correct?

When 250. mL of a 0.15 M solution of ammonium sulfide (NH₄)₂S is poured into 120. mL of a 0.053 M solution of cadmium sulfate CdSO₄, how many grams of a yellow precipitate of cadmium sulfide CdS are formed? The other product is (NH₄)₂SO₄. (Hint: Write the balanced chemical reaction equation).

The relative atomic mass of boron, which consists of isotopes ¹⁰₅B and ¹¹₅B is 108.8. What is the percentage of ¹¹₅B atoms in the isotropic mixture?

In an attempt to establish the formula of an oxide of nitrogen, a known volume of the pure gas was mixed with hydrogen and passed over a catalyst at a suitable temperature. 100% conversion of the oxide to ammonia and water was shown to have taken place.

N_xO_y + H₂ → xNH₃ + yH₂O

2400 cm³ of the oxide of nitrogen, measured at room temperature and pressure ( R.T.P), produced 7.20g of water. The ammonia produced was neutralized by 200cm³ of 1.0 mol/dm³ HCl.

[Molar volume of gas at R.T.P = 24000cm³ mol^-1]

What is the molecular formula of the oxide of nitrogen? (correct answer)

Crystal system characterized by a ≠ b≠ c and α = β = γ = 90^o

Hydrogen Bonds typically occur between atoms of hydrogen involved in this type of bond:

What is the name for a substance that dissolves in water but does not form ions or conduct an electric current?

The optical properties of liquid crystals depend on the direction of ___________

The correct way of making a solution of acid in water is to

A student extracts the colour from some green smarties and uses paper chromatography to separate components colours. She finds blue has a R_f =0.38 and yellow R_f =0.75 this suggests