Answer: 1.
moles
2. 90 mg
Explanation:

According to stoichiometry:
1 mole of ozone is removed by 2 moles of sodium iodide.
Thus
moles of ozone is removed by =
moles of sodium iodide.
Thus
moles of sodium iodide are needed to remove
moles of 
2. 
According to stoichiometry:
1 mole of ozone is removed by 2 moles of sodium iodide.
Thus 0.0003 moles of ozone is removed by =
moles of sodium iodide.
Mass of sodium iodide=
(1g=1000mg)
Thus 90 mg of sodium iodide are needed to remove 13.31 mg of
.
Answer:
29 L.
Explanation:
Hello!
In this case, considering that we are performing a conversion by which the time should be cancelled out to obtain liters, we first need to convert the seconds on bottom to hours and then the volume on top to liters, just a shown down below:

Which turns out 29 L with 2 significant figures.
Best regards!
Answer: 48800g
Explanation:
Using the mathematical relation : Moles = Mass / Molar Mass
Moles = 488
Molar mass of CaCO3 = 40 + 12 + (16 x 3) = 100g/mol
Therefore
488 = mass / 100 = 48800g
Answer:
C8H8 + 10O2 → 8CO2 + 4H2O
Explanation:
unbalanced reaction:
C8H8 + O2 → CO2 + H2O
balanced for semireactions:
(1) 16H2O + C8H8 → 8CO2 + 40H+
(2) 10(4H+ + O2 → 2H2O)
⇒ 40H+ + 10O2 → 20H2O
(1) + (2):
balanced reaction:
⇒ C8H8 + 10O2 → 8CO2 + 4H2O
8 - C - 8
20 - O2 - 20
8 - H - 8