Answer: 4.56 Joules
Explanation:-
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

Q = Heat absorbed = ?
m= mass of substance = 2.5 g
c = specific heat capacity = 
Initial temperature =
= 25.0°C
Final temperature =
= 29.9°C
Change in temperature ,
Putting in the values, we get:


The heat absorbed by gallium must be 4.56 Joules
There are 12<span> protons and </span>10<span> electrons in a </span><span>Mg<span>2+</span></span><span> ion, the normal amount of neutrons is </span>12<span>.</span>
Answer:
1.60.
Explanation:
- The no. of millimoles of HCl = MV = (0.15 M)(20.0 mL) = 3.0 mmol.
- The no. of millimoles of KOH = MV = (0.10 M)(20.0 mL) = 2.0 mmol.
<em>Since the no. of millimoles of HCl is larger than that of KOH. The solution is acidic.</em>
<em></em>
∴ M of remaining HCl [H⁺] remaining = (NV)HCl - (NV)KOH/V total = (3.0 mmol) - (2.0 mmol) / (40.0 mL) = 0.025 M.
∵ pH = - log[H⁺]
<em>∴ pH = - log[H⁺] </em>= - log(0.025) = <em>1.602 ≅ 1.60.</em>