1) Answer is: 1,425 moles oftin(IV) chloride are formed.
Chemical reaction: 2Cl₂ + Sn → SnCl₄.
n(Cl₂) = 2,85 mol.
From chemical reaction: n(Cl₂) : n(SnCl₄) = 2 : 1.
n(SnCl₄) = n(Cl₂) ÷ 2.
n(SnCl₄) = 2,85 mol ÷ 2.
n(SnCl₄) = 1,425 mol.
n - amount of substance.
2) Answer is: mass of lithium is 128,04 grams.
Chemical reaction: 6Li + N₂ → 2Li₃N.
m(N₂) = 86,1 g.
n(N₂) = m(N₂) ÷ M(N₂).
n(N₂) = 86,1 g ÷ 28 g/mol.
n(N₂) = 3,075 mol.
From chemical reaction: n(N₂) : n(Li) = 1 : 6.
n(Li) = 6 · 3,075 mol.
n(Li) = 18,45 mol.
m(Li) = 18,45 mol · 6,94 g/mol.
m(Li) = 128,04 g.
3) Answer is: 69,77 grams of oxygen can be produced.
Chemical reaction: 2Cr(ClO₃)₃ → 2CrCl₃ + 9O₂.
m(Cr(ClO₃)₃) = 146,5 g.
n(Cr(ClO₃)₃) = m(Cr(ClO₃)₃) ÷ M(Cr(ClO₃)₃).
n(Cr(ClO₃)₃) = 146,5 g ÷ 302,35 g/mol.
n(Cr(ClO₃)₃) = 0,48 mol.
From chemical reaction: n(Cr(ClO₃)₃) : n(O₂) = 2 : 9.
n(O₂) = 2,18 mol.
m(O₂) = 2,18 mol · 32 g/mol.
m(O₂) = 69,77 g.
4) Answer is: volume of hydrogen is 97,47 dm³.
Chemical reaction: 2Al + 6H₂O → 2Al(OH)₃ + 3H₂.
m(Al) = 78,33 g.
n(Al) = m(Al) ÷ M(Al).
n(Al) = 78,33 g ÷ 27 g/mol.
n(Al) = 2,9 mol.
From chemical reaction: n(Al) : n(H₂) = 2 : 3.
n(H₂) = 2,9 mol · 3 ÷ 2.
n(H₂) = 4,35 mol.
V(H₂) = n(H₂) · Vm.
V(H₂) = 4,35 mol · 22,4 dm³/mol.
V(H₂) = 97,47 dm³ (L).
Vm - molar volume.
5) Answer is: there is 5,47·10²⁴ atoms of copper.
Chemical reaction: 6Cu + N₂ → 2Cu₃N.
V(N₂) = 33,9 L.
n(N₂) = V(N₂) ÷ Vm.
n(N₂) = 33,9 L ÷ 22,4 L/mol.
n(N₂) = 1,513 mol.
From chemical reaction: n(N₂) : n(Cu) = 1 : 6.
n(Cu) = 6 · 1,513 mol.
n(Cu) = 9,08 mol.
N(Cu) = n(Cu) · Na.
N(Cu) = 9,08 mol · 6,022·10²³ 1/mol.
N(Cu) = 5,47·10²⁴.
Na - Avogadro number.
