Answer:
1.8 moles of O₂
Explanation:
The balance chemical equation for said double replacement (photosynthesis) reaction is as follow;
6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂
According to balance chemical equation,
6 moles of O₂ are produced by = 6 moles of CO₂
So,
1.8 moles of O₂ will be produced by = X moles of O₂
Solving for X,
X = 1.8 mol × 6 mol / 6 mol
X = 1.8 moles of O₂
Stoichiometric problems in which moles are given and moles or other reactant or product asked are the simplest problems. One should only write the balanced chemical equation and perform above method to find the required moles.
Answer: Hydrogen gas will be given off
Explanation:
Whenever a metal reacts with an acid, a salt of the metal is formed and hydrogen gas is given off.
For instance: The reaction of Zinc metal on Hydrochloric acid.
Zn(s) + 2HCl(aq) ---> ZnCl2(aq) + H2(g)
From the equation provided, hydrogen gas is given off as a by-product
Answer : The volume of 4.9 M 
stock solution used to prepare the solution is, 12.24 ml
Solution : Given,
Molarity of aqueous solution = 1.20 M = 1.20 mole/L
Volume of aqueous solution = 50.0 ml = 0.05 L
(1 L = 1000 ml)
Molarity of stock solution = 4.9 M = 4.9 mole/L
Formula used :
where,
= Molarity of aqueous solution
= Molarity of stock solution
= Volume of aqueous solution
= Volume of stock solution
Now put all the given values in this formula, we get the volume of stock solution.
By rearranging the term, we get
Therefore, the volume of 4.9 M stock solution used to prepare the solution is, 12.24 ml
