Answer:
The heat of reaction is basically the energy that is being released and or absorbed when chemicals are transformed in a type of chemical reaction. However, the heat of reaction or also called reaction enthalpy is mostly or typically expressed as a molar enthalpy in kJ/mol and or as just a specific enthalpy in kJ/kg or kJ/L.
The quantity of heat absorbed is 33.4 kJ.
Δ<em>H</em>_fus = 334 J·g⁻¹
<em>q = m</em>Δ<em>H</em>_fus = 100.0 g × 334 J·g⁻¹ = 3.34 × 10⁴ J = 33.4 kJ
Answer: 4.18925 kJ heat is needed to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.
Explanation:
Temperature of Solid 
Melting temperature of Solid 
Temperature of liquid 
Specific heats of solid ethanol = 0.97 J/gK
Specific heats of liquid ethanol = 2.3 J/gK
Heat required to melt the the 25 g solid 
at 159 K
= 159 K - 138 K = 21 K
Heat required to melt and raise the temperature of upto 223 K
= 223 K - 159 K = 64 K
Total heat to convert solid ethanol to liquid ethanol at given temperature :
(1kJ=1000J)
Hence, 4.18925 kJ of heat will be required to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.
If you change the subscripts it would change the reactants or products and then you would be solving a different formula, you would change what the chemical is
Answer: Option (c) is the correct answer.
Explanation:
Plants used to prepare food in the presence of sunlight. Therefore, plants uses solar energy to make food.
Due to solar energy various chemical reactions take place in the food.
Thus, we can conclude that chemical energy is stored in our food and this chemical energy start out as light energy from the sun.
