Answer:
0.5059kg
Explanation:
The heat absorbed for the water is determined using the equation:7
Q = C×m×ΔT
<em>Where Q is heat absorbed (4300cal)</em>
<em>C is specific heat (1cal/g°C)</em>
<em>m is the mass in grams</em>
<em>ΔT is change in °C (101.0°C - 92.5°C = 8.5°C)</em>
<em />
Replacing:
4300cal = 1cal/g°C×m×8.5°C
505.9g = m
In kg, the mass of water is:
<h3>0.5059kg</h3>
<em />
We are given with the mass of pure iron that reacts with oxygen to form an oxide which has a given mass as well. the mass of oxygen reacted is 8.15-6.25 g or 1.9 grams. THen we convert the mass of the reactants to moles. Iron is equal to 0.1119 moles and oxygen is equal to 0.1188. We divide each number to the less amount. Hence iron is 1 and oxygen is approx 1. The empirical formula hence is FeO or ferrous oxide or Iron (II) oxide.
<u>Given:</u>
Change in internal energy = ΔU = -5084.1 kJ
Change in enthalpy = ΔH = -5074.3 kJ
<u>To determine:</u>
The work done, W
<u>Explanation:</u>
Based on the first law of thermodynamics,
ΔH = ΔU + PΔV
the work done by a gas is given as:
W = -PΔV
Therefore:
ΔH = ΔU - W
W = ΔU-ΔH = -5084.1 -(-5074.3) = -9.8 kJ
Ans: Work done is -9.8 kJ
10.0gNaCl/2.0Lsolution= 5.0g/L