Chemistry Past Questions and Answers

Use the options above to answer this question. Which is the structural formula for pent-2-enoic acid?

Question 42:

10cm³ of hydrogen fluoride gas react with 5cm³ of dinitrogen difluoride gas (N²F₂) to form 10₃ of a single gas. Which of the following is the most likely equation of the reaction?

A HF + N₂F₂ \(\to\) N₂HF₃
B 2HF + N₂F₂ \(\to\) 2NHF₂
C 2HF + N₂F₂ \(\to\) N₂H₂F₃
D HF + 2N₂F₂ \(\to\) N₄HF₂

Question 43:

The number of atoms of chlorine present in 5.85g of NaCl is [Avogaro's Number = 6.02 x 10²³]

A 6.02 x 10²²
B 5.85 x 10²³
C 6.02 x 10²³
D 5.85 x 10²⁴

Question 44:

How much of magnesium is required to react with 260cm³ of 0.5 M HCl? [Mg = 24]

A 0.3g
B 1.5g
C 2.4g
D 3.0g

Question 45:

The relationship between the velocity (U) of gas molecules and their relative molecular mass (M) is shown by the equation

A U = (kM)\(\frac{1}{2}\)
B U = (kM)²
C U = \(\sqrt{\frac{k}{m}}\)
D U = \(\frac{k}{m}\)