6 protons it have to be neutral
The kind of thermochemical equation represented below
that is
CaO(s) + H2O (l) = Ca(OH)2 (s) +65.2 kj
is exothermic ( answer B)
This is because its heat energy has a + sign meaning that heat is released by the reaction above.
Answer:
Explanation:
<u>1) Convert the mass of water into number of moles</u>
- Molar mass of water: 18.015 g/mol
- Number of moles, n = mass in grams / molar mass
n = 255 g / 18.015 g/mol = 14.15 mol
<u>2) Use the formula E = n × ΔH vap</u>
This is, you have to multiply the molar ΔH vaporization by the number of moles to find the total energy to boil the given amount of water.
- E = 14.15 mol × 40,650 J/mol = 575,395.5 J
<u>3) Round to the correct number of significant figures.</u>
The mass of water is the measurement with the least number of significant figures (3), so you must report the answer with 3 significant figures,
4.7 M It may be wrong, but I hope it helps!
Explanation:
When you're diluting a solution, you're essentially keeping the number of moles of solute constant while changing the total volume of the solution.
Now, let's assume that you don't know the equation for dilution calculations.
In this case, you can use the molarity and volume of the concentrated solution to determine how many moles of hydrochloric acid you start with.
c
=
n
V
⇒
n
=
c
⋅
V
n
HCl
=
18 M
⋅
190
⋅
10
−
3
L
=
3.42 moles HCl
You then add water to get the total volume of the solution from
190 mL
to
730 mL
.
The number of moles of hydrochloric acid remains unchanged, which means that the molarity of the diluted solution will be
c
=
3.42 moles
730
⋅
10
−
3
L
=
4.7 M
Answer:
I am not quite sure about it, i think it is because of the fact that mercury has weight, when it is filled with mercury, it will expand a little bit.
