2 A student put 25.0 cm of dilute hydrochloric acid into a conical flask.
The student added 2.5g of solid sodium carbonate and measured the change in temperature of
the mixture.
Which apparatus does the student need to use to obtain the most accurate results?
A balance, measuring cylinder, thermometer
B balance, pipette, stopwatch
C balance, pipette, thermometer
D
burette, pipette, thermometer

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)

Explaination:

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)

hope it helps :)