Answer:
Well they help us understand the properties of matter of course!
The density is calculated as mass per volume, so if we want to solve for mass, we would multiply density by volume.
For Part A: if we have a density of 0.69 g/mL, and a volume of 280 mL, multiplying these will give a mass of: (0.69 g/mL)(280 mL) = 193.2 g. Rounded to 2 significant figures, this is 190 g gasoline.
For Part B: if we have a density of 0.79 g/mL, and a volume of 190 mL, multiplying these will give a mass of: (0.79 g/mL)(190 mL) = 150.1 g. Rounded to 2 significant figures, this is equal to 150 g ethanol.
The mass of CO₂ gas = 4.312 g
<h3>Further explanation</h3>
Reaction
NaHCO₃ (s) + HCl (aq) → NaCl (aq) + H₂O (aq) + CO₂ (g)
Find limiting reactant
mol NaHCO₃

mol HCl

Limiting reactant : NaHCO₃ (smaller)
mol CO₂ = mol NaHCO₃ = 0.098
mass CO₂ :

Because the copper roofs, have been outside for a while and oxidization has occurred.
When metals become oxidized they rust, but when copper becomes oxidized, it turns greenish.
So copper roofs oxidize and turn green from being outside and a copper square doesn’t if it’s inside.
Answer:
0.0125 moles of HCl
Explanation:
(0.50 mol/L)(0.025 L) = 0.0125 moles of HCl