Answer:
ΔE = -2661 KJ/mole
ΔH = -2658 KJ/mole
Explanation:
ΔH = q - PΔV
ΔE = q + w
<u>First, to find ΔE:</u>
The reaction PRODUCES 2658 kJ of h (q), and does 3 kJ of work (w).
2658 kJ(q) + 3 kJ(w) = 2661 kJ, BUT the reaction <u><em>PRODUCES</em></u> heat, which means ΔE is negative.
ΔE = -2661 KJ/mole
<u>Second, to find ΔH:</u>
ΔH = q - PΔV
ΔH = 2658 kJ(q) - PΔV
Now, the question states that butane burns at a constant pressure; that just translates to the pressure of the reaction is equal to 0.
ΔH = 2658 KJ(q) - (0)ΔV
ΔH = 2658 KJ - 0
ΔH = 2658 kJ, BUT, like before, the reaction PRODUCES heat, which also mean ΔH is negative.
ΔH = -2658 KJ/mole
I hope this helped! Have a nice week.
Answer:

Explanation:
Hello,
In this case, one considers that the heat lost by the water is gained by the steel rod:

That in terms of masses, heat capacities and temperatures is:

Thus, solving for the mass of the steel rod, we obtain:

Best regards.
<u>Answer:</u> The formula of chromic acid is 
<u>Explanation:</u>
We are given an ionic compound named as chromic acid. This acid is formed by the combination of hydrogen ion and chromate ion.
An acid is defined as the substance which releases hydrogen ion when dissolved in water.
Hydrogen is the 1st element of periodic table having electronic configuration of
.
This element will loose 1 electron to form
ion.
Chromate ion is a polyatomic ion having chemical formula of 
By criss-cross method, the oxidation state of the ions gets exchanged and they form the subscripts of the other ions. This results in the formation of a neutral compound.
So, the chemical formula for the given compound is 
Thus, the formula of chromic acid is 
Answer:
Because the most reactive elements are<em> HALOGENS</em>.
1 mole H2O ---------------------- 6.02x10²³ molecules
4 moles H2O--------------------- y molecules
y = 4 * 6.02x10²³
y = 2.4x10^24 molecules
answer b
hope this helps!.