Explanation:
A system can be either closed or open; A closed system is a system that is completely isolated from its environment. An open system is a system that has flows of information, energy, and/or matter between the system and its environment, and which adapts to the exchange.
Answer is: 55.125 grams <span>of propane must be burned.
</span>Balanced chemical reaction: C₃H₈ + 5O₂ → 3CO₂ + 4H₂O.
Make proportion: 1 mol(C₃H₈) : 2220 kJ = n(C₃H₈) : 2775kJ.
n(C₃H₈) = 2775 kJ·mol ÷ 2220 kJ.
n(C₃H₈) = 1.25 mol.
m(C₃H₈) = n(C₃H₈) · M(C₃H₈).
m(C₃H₈) = 1.25 mol · 44.1 g/mol.
m(C₃H₈) = 55.125 g.
n - amount of substance.
Answer:
The body with 2.7 
has a larger volume
Explanation:
There is a missespelling in the question. The units of density cannot be g, they usually are
In order to answer this question, we need to use the formula of the density of a body:
For body A:
Mass (M) = 5.0 g
Density (D) = 2.7
2.7 = 5g * 1/V
V1 = 5g / (2.7 )
V1 = 1.85 
For Body B:
Mass (M) = 5.0 g
Density (D) = 8.4
8.4 = 5g * 1/V
V2 = 5g / (8.4 )
V2 = 0.59
So V1 is bigger than V2
