Given parameters:
Heat of fusion of water = 334j/g
Mass of ice = 45g
Temperature of ice = 0.0°c
Unknown:
Amount of heat needed to melt = ?
Solution:
This is simply a phase change and a latent heat is required in this process.
To solve this problem; use the mathematical expression below;
H = mL
where m is the mass
L is the heat of fusion of water;
H = 45 x 334 = 15030J
Answer:
The amount of thermal energy stored in an object depends on three things.
- The mass of the object.
- The temperature of the object.
- The amount of energy that the particular material stores per degree of temperature.
MgBr2(aq) is an ionic compound which will have the releasing of 2 Br⁻ ions ions in water for every molecule of MgBr2 that dissolves.
MgBr2(s) --> Mg+(aq) + 2 Br⁻(aq)
[Br⁻] = 0.51 mol MgBr2/1L × 2 mol Br⁻ / 1 mol MgBr2 = 1.0 M
The answer to this question is [Br⁻] = 1.0 M
Specific gravity is the ratio of density of substance and density of water
We know that density of water = 1 g /mL at standard conditions
now as given that the 0.8 Kg of the substance / object is able to displace 500mL of water , it means that
Mass of object = 800g
The volume occupied by 800g of object = 500 mL
Density = mass / volume
Density of object = 800 / 500= 1.6 g / mL
The specific gravity of object = density of object / density of water = 1.6 / 1 = 1.6 (no units)
