Ferromagnesian silicate minerals (i looked it up)
<u>Answer:</u> The correct answer is Option A.
<u>Explanation:</u>
Standard enthalpy of formation is the change in enthalpy of one mole of a substance present at the standard state that is 1 atm of pressure and 298 K of temperature. The substance is formed from its pure elements under the same conditions.
We are given a chemical compound having chemical formula 
This compound is formed by the combination of calcium, nitrogen and oxygen elements.
The chemical equation for the formation of
from the components in their standard states follows:

Hence, the correct answer is Option A.
Answer:
The evidence showing that there is a chemical reaction taking place is the instantaneous temperature drop once the cold pack is shaken.
Explanation:
When an athlete applies a cold pack to the injury, they shake it before, mixing the water and <em>ammonium-nitrate fertilizer</em> inside the cold pack. This mixing is an endothermic reaction, which means it absorbs heat. In turn, the temperature falls to 35 F for around 10 minutes.
Answer:
Reactions 1, 3 and 5
Explanation:
First thing's first, let's ensure that all the reactions given are balanced. This is given as;
CO(g) + 1/2 O2(g )→ CO2(g)
Li(s) + 1/2 F2(l) → LiF(s)
C(s) + O2(g) → CO2(g)
CaCO3(g) → CaO + CO2(g)
2Li(s) + F2(g) → 2LiF(s)
For the condition to be valid;
- There is by convention 1 mol of product made. This means we eliminate reactions with more than one mole of compound formed. This eliminates reaction 5.
- The lements haveto be in their state at room temperature. Fluorine is a gas, not a liquid, at room temperature ans pressure, so 2 is not a correct answer.
This leaves us with reactions 1, 3 and 5 as the correct reactions that satisify the condition.
Answer : q = 6020 J, w = -6020 J, Δe = 0
Solution : Given,
Molar heat of fusion of ice = 6020 J/mole
Number of moles = 1 mole
Pressure = 1 atm
Molar heat of fusion : It is defined as the amount of energy required to melt 1 mole of a substance at its melting point. There is no temperature change.
The relation between heat and molar heat of fusion is,
(in terms of mass)
or,
(in terms of moles)
Now we have to calculate the value of q.

When temperature is constant then the system behaves isothermally and Δe is a temperature dependent variable.
So, the value of 
Now we have to calculate the value of w.
Formula used : 
where, q is heat required, w is work done and
is internal energy.
Now put all the given values in above formula, we get

w = -6020 J
Therefore, q = 6020 J, w = -6020 J, Δe = 0