TEFA: GCE A/L

May 13, 2022, 7:11 a.m.
Wanyu
Question:

A highly insulated calorimeter contains 0.050 kg of ice and 0.1 kg of water. Steam at 100°C is passed in until the ice melts. Determine the

a) quantity of water now in the calorimeter

b) equilibrium temperature if the mass of steam is doubled. State any assumption made in your calculation.

Solution

a) Total mass of water equals the sum of the initial mass of water, mass of melted ice and mass of condensed steam.

Heat lost by steam in melting equals heat gained by ice in melting

$m_{s}l_{v}=m_{i}l_{f}\Rightarrow m_{s}=\frac{m_{i}l_{f}}{l_{v}}\\ \Rightarrow m_{s}=\frac{0.050\ kg\times 334\ kJkg^{-1}}{2260\ kJkg^{-1}}=0.007\ kg$

Total mass of water,

$m=0.10\ kg+0.050\ kg+0.007\ kg\Rightarrow {\color{Red} m=0.157\ kg}$

b) Heat lost by steam in condensing and cooling equals heat gained by ice in melting and heat gained by water and melted ice in warming.

$2m_{s}l_{v}+2m_{s}c(100\degree C-\theta)=m_{i}l_{f}+(m_{i}+m_{w})c(\theta-0\degree C)\\ \Rightarrow \theta (m_{i}+m_{w}+2m_{s})c=2m_{s}(l_{v}+100\degree C*c)-m_{i}l_{f}\\ \Rightarrow \theta =\frac{2m_{s}(l_{v}+100\degree C*c)-m_{i}l_{f}}{(m_{i}+m_{w}+2m_{s})c}\\ \\ \Rightarrow \theta =\frac{2*0.007\ kg(2260\ kJkg^{-1}+100\degree C*4.2\ kJkg^{-1}K^{-1})-0.050\ kg*334\ kJkg^{-1}}{(0.050\ kg+0.10\ kg+2*0.007\ kg)4.2\ kJkg^{-1}K^{-1}}\\ \\ \Rightarrow \theta = \frac{37.52-16.7}{0.6888}\ \degree C\\ \\ {\color{Red} \Rightarrow \theta = 30\degree C}$

Assumptions made:

Heat losses are negligible since the calorimeter is well lagged

Heat gained by calorimeter is negligible

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May 13, 2022, 6:41 a.m.
Ndi
A highly insulated calorimeter contains 0.050 kg of ice and 0.1 kg of water. Steam at 100°C is passed in until the ice melts. Determine the

a) quantity of water now in the calorimeter

b) equilibrium temperature if the mass of steam is doubled. State any assumption made in your calculation.

0

Reply
- May 13, 2022, 7:12 a.m.
  Wanyu
  You can check the solution already. Thanks for asking the question.
  
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March 24, 2022, 2:46 p.m.
Solomon Bless
This is good

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Feb. 6, 2022, 4:45 p.m.
Wilson
I phase problems in mechanics under momentum (firing a gun)

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- Feb. 11, 2022, 12:16 p.m.
  Yuyen
  Please are you versed with dimensions and motion???
  
  0
Jan. 30, 2022, 12:01 a.m.
Favoures
My problem is simple why is fields so complicated to understand too many formulas

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- June 19, 2022, 1:37 p.m.
  Yuyen
  You can start by following the lessons under fields. I believe it will be of help https://tefaafrik.com/SCHOOL/Course/109/Video
  
  0
Jan. 29, 2022, 11:28 a.m.
KAMBIET TEMO ANGE LUC
I face many difficulties in physics especially fields

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Jan. 29, 2022, 11:26 a.m.
Obam Erna
I have face problems in fields

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- Feb. 5, 2022, 3:22 p.m.
  lynn
  quite beautriful
  
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Jan. 29, 2022, 11:21 a.m.
KENG ElSON
i face problems in mechanics

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