<h3>
Answer:</h3>
1379.4 Joules
<h3>
Explanation:</h3>
- The quantity of heat is calculated multiplying the mass of a substance by heat capacity and the change in temperature.
Therefore;
Quantity of heat = Mass × specific heat capacity × Change in temperature
Q = mcΔT
In this case;
The substance dissolved in water gained heat while water lost heat energy.
Thus, Heat gained by the substance = heat lost by water
Heat associated with the water
Mass of water = 75 g
Change in temperature = 4.4°C
Specific heat capacity = 4.18 J/g·⁰C
Heat = mcΔT
= 75 g × 4.18 J/g·⁰C × 4.4 °C
=1379.4 Joules
Answer: C, 146
Explanation:
NaCl has a molar mass of 58.44 g/mol.
To change moles to g, we do:
2.50 moles × 58.44 g/mol = 146.1 g, so C
The relative molecular mass of acid A : 50 g/mol
<h3>Further explanation</h3>
Given
40.0 cm³(40 ml) of 0.2M sodium hydroxide
0.2g of a dibasic acid
Required
the relative molecular mass of acid A
Solution
Titration formula
M₁V₁n₁=M₂V₂n₂
n=acid/base valence(number of H⁺/OH⁻)
NaOH ⇒ n = 1
Dibasic acid = diprotic acid (such as H₂SO₄)⇒ n = 2
mol = M x V
Input the value in the formula :(1 = NaOH, 2=dibasic acid)
0.2 x 40 x 1 = M₂ x V₂ x 2
M₂ x V₂ = 4 mlmol = 4.10⁻³ mol ⇒ mol of Acid A
The relative molecular mass of acid A (M) :
A. high potential energy and zero kinetic energy.