IB Chemistry Option A

The volume of an ideal gas at 27.0 °C is increased from 3.00 dm3 to 6.00 dm3. At what temperature, in °C, will the gas have the original pressure?

• 13.5

• 54.0

• 327

• 600

What is the sum of all coefficients when the following equation is balanced using the smallest possible whole numbers?

__ C2H2 + __O2 → __CO2 + __H2O

• 5

• 7

• 11

• 13

1.7 g of NaNO3 (Mr = 85) is dissolved in water to prepare 0.20 dm3 of solution. What is the concentration of the resulting solution in mol dm–3?

• 0.01

• 0.1

• 0.2

• 1.0

How many molecules are present in a drop of ethanol, C2H5OH, of mass 2.3 × 10^–3 g?

(L = 6.0 × 10²³ mol–1)

• 3.0 × 10 ¹⁹

• 3.0 × 10²⁰

• 6.0 × 10²⁰

• 6.0 × 10²⁶

Which sample has the greatest mass?

• 1 mol of SO₂

• 2 mol of N₂O

• 2 mol of Ar

• 4 mol of NH₃

Tags

NGSS.HS-PS1-7

The relative molecular mass of a gas is 56 and its empirical formula is CH₂. What is the molecular formula of the gas?

• CH₂

• C₂H₄

• C₃H₆

• C₄H₈

What mass, in g, of hydrogen is formed when 3 mol of aluminium react with excess hydrochloric acid according to the following equation?

2Al(s) + 6HCl(aq) → 2AlCl₃(aq) + 3H₂(g)

• 3.0

• 4.5

• 6.0

• 9.0

Tags

NGSS.HS-PS1-7

What is the total number of hydrogen atoms in 1.0 mol of benzamide, C₆H₅CONH₂?

• 7

• 6.0 × 10²³

• 3.0 × 10²⁴

• 4.2 × 10²⁴

Tags

NGSS.HS-LS1-6

What is the sum of the coefficients for the equation when balanced using the smallest possible whole numbers?

__N₂H₄(g) + __O₂(g) → __NO₂(g) + __H₂O(g)

• 5

• 6

• 7

• 8

A fixed mass of gas has a certain volume at a temperature of 50 °C. What temperature is required to double its volume while keeping the pressure constant?

• 100 K

• 323 K

• 373 K

• 646 K