<u>Answer:</u>
<em>1) ∆H is positive
Endothermic
</em>
<em>2)
Endothermic </em>
<em>3) Energy is absorbed
Endothermic
</em>
<em>4)
Exothermic
</em>
<em>5) ∆H is negtive
Exothermic
</em>
<em></em>
<u>Explanation:</u>
∆H is called as enthalpy change
It is also called as Heat of reaction
Energy is required for the bond to break a bond.
Energy is released when a bond is formed.

that is

We see in this equation, bonds between hydrogen and chlorine molecules gets broken and on the right side bond is formed in HCl.
If energy of products greater than energy of reactants then the reaction enthalpy change is endothermic .
If energy of products lesser than energy of reactants then the reaction enthalpy change is exothermic .
For example



(positive hence endothermic)



(negative hence exothermic)
Answer:
15 people x 4 slices so you’ll need 60 pieces
60/12(the amount of slices per pizza) =5
You need 5 pizzas. $14.78 x 5 = 73.90.
Explanation:
the answer is that one 73.90 is rounded nearest cent : ) took me a while to get it
Answer:
10
Explanation:
pH is defined as the negative logarithm of the concentration of hydrogen ions.
Thus,
pH = - log [H⁺]
Thus, from the formula, more the concentration of the hydrogen ions or more the acidic the solution is, the less is the pH value of the solution.
Thus, solution with pH = 3 will be more acidic than solution with pH =4
Thus, concentration of the [H⁺] when pH =3
3 = - log [H⁺]
[H⁺] = 10⁻³ M
For pH = 4, [H⁺] = 10⁻⁴ M
<u>hence, pH = 3 is 10 times more acidic than pH = 4</u>
Answer: Ionic compounds are compounds consisting of ions.
Two-element compounds are usually ionic when one element is a metal and the other is a non-metal
Explanation: hope this helps!
Volume<span> of matter </span>decreases<span> under </span>pressure<span> ... -under </span>pressure<span>, the </span>particles<span> in a </span>gas<span> are </span>forced closer together<span> ... </span>factors<span> affecting </span>gas pressure<span> ... -</span>if pressure<span> in a sealed container is </span>lower than<span> outside, </span>gas will<span> rush in ...</span>