Answer:
a. Endothermic
b. 26.37kJ/mol
Explanation:
a. As we can see, the temperature of the water is decreasing when the reaction is occurring, that means the reaction is absorbing heat and is endothermic
b. To find the enthalpy we must find the change in heat when 12.1g of KCl are dissolved. Using the equation:
Q = -m*ΔT*C
<em>Where Q is change in heat</em>
<em>m the mass of solution (250g + 12.1g = 262.1g)</em>
<em>ΔT is change in heat (17.1°C - 21.0°C = -3.9°C)</em>
<em>And C is specific heat of the solution (4.184J/g°C assuming is the same than the specific heat of water).</em>
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Replacing:
Q = -262.1g*-3.9°C*4.184J/g°C
Q = 4277J = 4.28kJ
As reaction enthalpy is the change in heat per mole of reaction, we must find the moles of 12.1g of KCl:
<em>Moles KCl -Molar mass: 74.55g/mol-:</em>
12.1g KCl * (1 mol / 74.55g) = 0.1623 moles KCl
The reaction enthalpy us:
4.28kJ / 0.1623mol = }
<h3>26.37kJ/mol</h3>
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Answer:
seasons experienced by the northern and southern hemisphere always differ by six months when it is summer in the northern hemisphere, it is winter in the southern hemisphere
Explanation:
I think it is the gas and the heat in it
Answer:
9.606 grams of citric acid are present in 125 mL of a 0.400 M citric acid solution.
Explanation:
Molarity : It is defined as the number of moles of solute present in one liter of solution. Mathematically written as:
Moles of citric acid = n
Volume of the citric acid solution = 125 mL =125 × 0.001 L= 0.125 L
(1 mL = 0.001L)
Molarity of the citric acid solution = 0.400 M
n = 0.400 M × 0.125 L = 0.05 moles
Mass of 0.05 moles of citric acid :
9.606 grams of citric acid are present in 125 mL of a 0.400 M citric acid solution.