Answer: the electrostatic potential energy is -3.26 × 10⁻¹⁸ J
Explanation:
Given the data in the question;
I think the value of electrostatic potential energy of calcium sulfide CaS formed will be less(more negative) than KCl because the Ca2+ and S2- ions has more charge that is +2 and -2 respectively when compared to Kcl which has +1 and -1 charge.so it will be more negative.
radius = r
+ r
= 100 + 184 = 284 pm = 2.84 × 10⁻¹⁰ m
we know that; k = 2.31 × 10⁻²⁸ J
q1 = 2 ( charge on Ca⁺² )
q2 = -2( charge on S⁻²)
so
Ep = k × q1q2/r
so we substitute
Ep = 2.31 × 10⁻²⁸ × (+2×-2) / 2.84 × 10⁻¹⁰
Ep = (2.31 × 10⁻²⁸ × -4) / 2.84 × 10⁻¹⁰
Ep = -9.24 × 10⁻²⁸ / 2.84 × 10⁻¹⁰
Ep = -3.26 × 10⁻¹⁸ J
Therefore, the electrostatic potential energy is -3.26 × 10⁻¹⁸ J
Let us define first what heat of hydrogenation means. This is commonly used as a measure of relative stability between two alkenes that result to the same alkane when it undergoes hydrogenation. The criteria is: the <em>smaller </em>the heat of hydrogenation, the more stable the alkene.
Answer : The specific heat of tungsten is, 
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.


where,
= specific heat of tungsten = ?
= specific heat of water = 
= mass of tungsten = 19.5 g
= mass of water = 78.5 g
= final temperature = 
= initial temperature of tungsten = 
= initial temperature of water = 
Now put all the given values in the above formula, we get


Therefore, the specific heat of tungsten is, 
Take 56 mL and subtract the original volume of 50 mL and that will give you the volume of the rock, which is 6mL.