<h3>Answer:</h3>
Phosphoric acid reacts with magnesium hydroxide to produce magnesium phosphate and water via the following reaction:
2H3PO4 + 3Mg(OH)2 → Mg3(PO4)2 + 6H2O
(solid) (solid) (solid) (liquid)
<h3>Explaination:</h3>
This is a typical neutralization reaction of an acid with a base to form a salt and water. The reaction is exothermic, gives off heat,
ΔH < 0 , and may be balanced by adding balancing numbers in front, ie adding molecules, in order to ensure that the total number of atoms of each element is the same on the left and right hand sides of the equation.
Doing so we obtain :
2H3PO4 + 3Mg(OH)2 → Mg3(PO4)2 + 6H2O
(solid) (solid) (solid) (liquid)
<h3>hope it helps :)</h3>
Answer:

Explanation:
We need to use the formula for heat of vaporization.

Identify the variables.
- The heat absorbed by the evaporating water is the <u>latent heat of vaporization. </u>For water, that is 2260 Joules per gram.
- Q is the energy, in this problem, 50,000 Joules.
- m is the mass, which is unknown.

Substitute the values into the formula.

We want to find the mass. We must isolate the variable, m.
m is being multiplied by 2260 J/g. The inverse operation of multiplication is division. Divide both sides by 2260 J/g.


Divide. Note that the Joules (J) will cancel each other out.


Round to the nearest whole number. The 1 in the tenth place tells us to leave the number as is.

The mass is about 22 grams, so choice B is correct.