Chemistry Stoichiometry

What is the sum of the coefficients when the following equation is balanced using whole numbers? ___ Fe₂O₃(s)+___ CO(g)→ ___ Fe(s)+ ___ CO₂(g)

• 5

• 6

• 8

• 9

How many moles of magnesium hydroxide are produced with 0.50 mol of ammonia? Mg₃N₂ (s) + 6H₂O (l) → 3Mg(OH)₂ (aq) + 2NH₃ (aq)

• 0.25

• 0.33

• 0.75

• 1.5

Tags

NGSS.HS-PS1-7

How many moles of FeS₂ are required to produce 32 g of SO₂? (A_r: S = 32, O = 16)

4FeS₂ (s) + 11O₂ (g) → 2Fe₂O₃ (s) + 8SO₂ (g)

• 0.25

• 0.50

• 1.0

• 2.0

16 g of bromine react with 5.2 g of metal, M, to form MBr₂. What is the relative atomic mass of the metal M? (A_r : Br = 80)

• 13

• 26

• 52

• 104

What is the value of x when 32.2 g of Na₂SO₄•xH₂O are heated leaving 14.2 g of anhydrous Na₂SO₄?

M_r(H₂O) = 18;

M_r(Na₂SO₄) = 142.

Na₂SO_4•xH₂O (s) → Na₂SO₄ (s) + xH₂O (g)

• 0.1

• 1

• 5

• 10

Tags

NGSS.HS-PS1-7

How many grams of sodium azide, NaN₃, are needed to produce 68.1 dm³ of N₂ (g) at STP? Molar volume at STP = 22.7 dm³ mol^–1 M_r(NaN₃) = 65.0 2NaN₃ (s) → 3N₂ (g) + 2Na (s)

• 32.5

• 65.0

• 130.0

• 195.0

How many moles of oxygen atoms are there in 0.500 mol of hydrated iron(II) ammonium sulfate, (NH₄)₂Fe(SO₄)₂•6H₂O(s)?

• 4.00

• 7.00

• 8.00

• 14.00

Which solution neutralizes 50.0 cm³ of 0.120 mol dm^–3 NaOH (aq)?

• 12.5 cm³ of 0.080 mol dm^–3 H₃PO₄

• 25.0 cm³ of 0.120 mol dm^–3 CH₃COOH

• 25.0 cm³ of 0.120 mol dm^–3 H₂SO₄

• 50.0 cm³ of 0.060 mol dm^–3 HNO₃

Tags

NGSS.HS-PS1-7

How many atoms are present in 0.500 mol of NH₃?

• 20×10²³

• 3.01×10²³

• 6.02×10²³

• 1.20×10²⁴

Which statements are correct about Avogadro’s constant?

• I and II only

• I and III only

• II and III only

• I, II and III

Tags

NGSS.HS-PS1-5

NGSS.HS-PS1-7