The answer is 33.33 %
The explanation:
According to the reaction equation:
MgCO3(s) + 2HCl (aq) --> MgCl2(aq) + H20(l) + CO2(g)
we can see that 1 mole of MCO3 will produce → 1 mole of CO2
-Now we need o get number of mole of CO2:
and when we have 0.22 g of CO2, so number of mole = mass / molar mass
moles = 0.22 g / 44 g/mol = 0.005 mole
∴ moles of Mg = moles of CO2 = 0.005 mole
∴ mass of Mg = moles * molar mass
= 0.005 * 84 /mol = 0.42 g
∴ Percent of MgCO3 by mass of Mg = 0.42 g / 1.26 * 100
= 33.33 %
I found another question like this. Someone answered "The best answer to this question is adding a catalyst.
Adding a catalyst will cause the greatest increase in the rate of reaction for this chemical reaction , 8Zn(s) + S8(s) 8ZnS(s). ---> adding a catalyst always affects the rate of a reaction."
THE ANSWER TO THE QUESTION IS A
Answer:
Cl⁻ was oxidized.
Explanation:
- 4HCl + MnO₂ → Cl₂ + 2H₂O + MnCl₂
Oxidation can be defined as the process in which the oxidation number of a substance increases.
On the left side of the equation, Cl has a charge of -1 (in HCl); while on the right side of the equation Cl has a charge of 0 in Cl₂.
Thus, Cl⁻ was oxidized.
