23/11 quiz

Which of these statements is incorrect?

• The atomic radius of metals increases down a Group.

• The trend in the melting temperature of successive elements across Period 2 is

  similar to that in Period 3.

• A metallic structure is held together by attractions between metal atoms and

  delocalized electrons.

• Na⁺

  and O²⁻

  ions are isoelectronic.

The electronic structure of an atom of an element in Group 6 of the Periodic Table could

be

• 1s²2s²2p²

• 1s²2s²2p⁴

• 1s²2s²2p⁶3s²3p⁶3d⁶

  4s²

• 1s²2s²2p⁶3s²3p⁶3d¹⁰

  4s²4p⁶

The electronic configurations of the atoms of four different elements are given below.

For which element would you expect the value of the first ionization energy to be the

largest?

• 1s¹

• 1s²

• 1s²2s¹

• 1s²2s²

Which of the following has the smallest ionic radius?

• F^–

• Na⁺

• Mg²⁺

• O^2-

A sample of gas was prepared for use in helium-neon lasers. It contained 4 g of helium

and 4 g of neon. What is the ratio of helium atoms to neon atoms in the sample?

• 1:1

• 2.5:1

• 1:5

• 5:1

The overall equation for the reaction between sulfur and oxygen to form sulfur trioxide

is shown below.

2S(s) + 3O₂(g) → 2SO₃(g)

0.9 mol of O2(g) reacted completely with excess sulfur. What volume, in dm³ , of

sulfur trioxide would form? [Assume the molar gas volume = 24 dm³ mol−1]

• (0.9 × 3/2) × 24

• (0.9 × 3/2) ÷ 24

• (0.9 × 2/3) × 24

• (0.9 × 2/3) ÷ 24

100 cm³ of hydrogen is mixed with 25 cm³ of oxygen at a temperature of 150^OC.

The gases react as shown in the equation below.

2H₂(g)+ O₂(g) ->2H₂O(g)

The total volume of gas present at the end of the reaction is

• 50

• 100

• 125

• 150

An excess of copper(II) oxide is mixed with 40.0 cm³ of 2.50 mol dm^–3 hydrochloric acid.

CuO(s) + 2HCl(aq) -> CuCl₂(aq) + H₂O(l)

If the mass of copper(II) chloride produced is 5.50 g, what is the percentage yield of copper(II) chloride?

[Molar mass of copper(II) chloride = 134.4 g mol^–1]

• 81.8%

• 67.2%

• 40.9%

• 20.4%

Complete combustion of a hydrocarbon produced 0.66 g of carbon dioxide and

0.225 g of water.

Which of the following molecular formulae is consistent with these data?

• C₃H₆

• C₃H₈

• C₆H₆

• C₆H₁₀

How many moles of atoms are present in 240 cm³ of carbon dioxide at room

temperature and pressure?

[1 mol of any gas occupies 24 dm³ at room temperature and pressure.]

• 0.010

• 0.020

• 0.024

• 0.030