Atoms and Reactions MC

How many neutrons does the isotopes boron-11 have?

• 5

• 6

• 11

• 16

How many electrons are found in a magnesium ion, Mg²⁺?

• 10

• 12

• 14

• 24

Europium has two isotopes. One is ¹⁵³Eu with an abundance of 52.23%. Which is the other isotope?

• ¹⁴⁹Eu

• ¹⁵⁰Eu

• ¹⁵¹Eu

• ¹⁵²Eu

Which is the correct formula for ammonium sulfate?

• NH₄SO₄

• NH₄(SO₄)₂

• (NH₄)₂SO₄

• N₂H₈SO₄

Which numbers are needed to balance the following equation?

C₈H₁₈ + 11 O₂ → ...... CO₂ + ..... CO + ....... H₂O

• 5, 3, 9

• 5, 3, 18

• 8, 1, 9

• 4, 4, 10

Which number represents the Avogadro constant?

• 6.20 x 10²³ g mol^-1

• 6.20 x 10²³ mol^-1

• 6.02 x 10²³ g mol^-1

• 6.02 x 10²³ mol^-1

Which is the correct pair of molecular and empirical formulae?

• C₄H₁₂, C₂H₆

• C₈H₁₈, C₄H₈

• C₆H₁₂, C₃H₆

• C₄H₈, CH₂

What is the pressure of 3 moles of gas in a 520 dm³ container at a standard temperature? The gas constant is 8.314 J mol^-1 K^-1

• 14.3 Pa

• 1199 Pa

• 14.3 kPa

• 14300 kPa

Which pair contains a strong acid and weak base?

• ethanoic acid and ammonia

• ethanoic acid and potassium hydroxide

• nitric acid and ammonia

• nitric acid and sodium hydroxide

Which statements about oxidation states of chlorine atoms are correct?

1) ClO₃^- is a chlorate(III) ion

2) ClO^- has chlorine in a +1 oxidation state

3) ClO₄^- has chlorine in a +7 oxidation state

• 1, 2 and 3

• only 1 and 2

• only 2 and 3

• only 1