Answer:
= 25.05°C
Explanation:
Given:
the value of ΔHcomb (heat of combustion) for dimethylphthalate (C10H10O4) is = 4685 kJ/mol.
mass = 0.905g of dimethylphthalate
molar mass = 194.18g dimethylphthalate
number of moles of dimethylphthalate = ???
= 21.5°C
= 6.15 kJ/°C
= ???
since we have our molar mass and mass of dimethylphthalate ;we can determine the number of moles as;
0.905g of dimethylphthalate × ![\frac{1 mole (dimethylphthalate)}{194.184g(dimethylphthalate)}](https://tex.z-dn.net/?f=%5Cfrac%7B1%20mole%20%28dimethylphthalate%29%7D%7B194.184g%28dimethylphthalate%29%7D)
number of moles of dimethylphthalate = 0.000466 moles
Heat released = moles of dimethylphthalate × heat of combustion
= 0.000466 moles × 4685 kJ
= 21.84 kJ
∴ Heat absorbed by the calorimeter =
![(T_f-T_i} )](https://tex.z-dn.net/?f=%28T_f-T_i%7D%20%29)
21.84 kJ =6.15 kJ/°C ![* (T_f-21,5^0C)](https://tex.z-dn.net/?f=%2A%20%28T_f-21%2C5%5E0C%29)
21.84 KJ = ![(6.15 kJ/^0C * T_f) - (6.15 kJ/^0C*21.5^0C)](https://tex.z-dn.net/?f=%286.15%20kJ%2F%5E0C%20%2A%20T_f%29%20-%20%286.15%20kJ%2F%5E0C%2A21.5%5E0C%29)
21.84 KJ =
- 132.225 kJ
21.84 KJ + 132.225 kJ = ![(6.15 kJ/^0C * T_f)](https://tex.z-dn.net/?f=%286.15%20kJ%2F%5E0C%20%2A%20T_f%29)
154.065 kJ = ![(6.15 kJ/^0C * T_f)](https://tex.z-dn.net/?f=%286.15%20kJ%2F%5E0C%20%2A%20T_f%29)
= ![\frac{154.065kJ}{6.15kJ/^0C}](https://tex.z-dn.net/?f=%5Cfrac%7B154.065kJ%7D%7B6.15kJ%2F%5E0C%7D)
=25.05°C
Answer : Option 3) Electrolysis.
Explanation : In the process of electrolysis, decomposition of the chemical is done by passing the electric current from the liquid or the solution containing ions in it. This is the process where compound is broken into ions namely, cations and anions.
Rest all options does not involves chemical decomposition of the compound.
Chromatography is a technique where rates of solute and solvent are compared in a medium where the solute components move at different rates and the separation is obtained.
Distillation simply purifies the liquid or solution by heating or cooling process.
Filtration just involves removal of impurities by using a more porous material device to get purified compound.
Answer:
lithium
Explanation:
this is because lithium has a valency of 1 and oxygen has a valency of 2 thereby exchanging valency to create Li²0
Answer:
Animals tend to use carbohydrates primarily for short-term energy storage, while lipids are used more for long-term energy storage. Carbohydrates are stored as glycogen in animals while lipids are stored as fats (in plants carbohydrates are stored as cellulose and lipids as oils)
Explanation:
hope this helps!
<span>Temperature is defined as the rate at which molecules move or vibrate
</span>