Answer:
C₂H₃₂
Explanation:
Given parameters:
Mass percentage of carbon = 42.88%
Mass percentage of hydrogen = 100 - 42.88 = 57.12%
Molecular weight = 56.02
Unknown:
Molecular formula = ?
Solution:
To solve this problem, we need to find the empirical formula of the compound first. The empirical formula is the simplest formula of a substance.
Therefore;
Elements Carbon Hydrogen
Percentage
composition 42.88 57.12
Molar mass 12 1
Number of moles 42.88/12 57.12/1
3.57 57.12
Simplest
ratio 3.57/3.57 57.12/3.57
1 16
Empirical formula of the compound is CH₁₆
Molar mass of CH₁₆ = 12 + 16(1) = 28g/mol
Multiplying index = = = 2
Molecular formula = (CH₁₆)₂ = C₂H₃₂
Answer:
Ca^2+(aq) + SO4^2-(aq) → CaSO4(s)
Explanation:
Step 1: The unbalanced equation
CaCl2(aq) + Na2SO4 (aq) → ...
Step 2: Balancing the equation
CaCl2(aq) + Na2SO4 (aq) → CaSO4 + NaCl
On the left side we have 2 times Cl (in CaCl2), On the right side we have 1 time Cl (in NaCl)
On the left side we have 2 times Na (in Na2SO4), on the right side we have 1 time Na (in NaCl)
To balanced the amount of Na and Cl we have to multiply NaCl, on the right side, by 2. Now the equation is balanced.
CaCl2(aq) + Na2SO4 (aq) → CaSO4(s) + 2NaCl(aq)
The net ionic equation, for which spectator ions are omitted - remember that spectator ions are those ions located on both sides of the equation - will look like this
Ca^2+(aq) + SO4^2-(aq) → CaSO4(s)