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Can somebody help me solve this ? I dont get how to do it

Can somebody help me solve this ? I dont get how to do it-example-1
User Linlin
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1 Answer

1 vote

Answer:

The mass of water is 25.9g.

Step-by-step explanation:

1st) It is necessary to use the Heat formula. Knowing that the piece of aluminum releases heat and the water absorbs heat, the equation is a sum of both heats euqal to zero:


Q_(Al)+Q_(water)=0

2nd) The information given in the exercise is:

• Piece of aluminum:

- Mass (mAl)=55.0g

- Heat capacity (cAl)=0.902J/°C*g

- Initial Temperature (TiAl)= 72.4°C

- Final Temperature (TfAl)= 44.9°C

• Water:

- Mass (mwater)= this is what we have to calculate.

- Heat capacity (cwater)= 4.18J/°C*g

- Initial Temperature (Tiwater)= 32.3°C

- Final Temperature (Tfwater)= 44.9°C

3rd) It is necessary to replace the values in the formula to calculate the mass of the aluminum piece:


\begin{gathered} -Q_(Al)=Q_(water) \\ -\lbrack m_(Al)*c_(Al)*(T_(fAl)-T_(iAl))\rbrack=m_(water)*c_(water)*\left(T_(fwater)-T_(iwater)\right) \\ -\lbrack55.0g*0.902(J)/(\degree C*g)*(44.9°C-72.4°C)\rbrack=m_(water)*4.18\frac{J}{\operatorname{\degree}C*g}*(44.9°C-32.3°C) \\ -\lbrack-1364.28J\rbrack=m_(water)*52.67\frac{J}{\operatorname{\degree}C} \\ (1364.28J)/(52.67(J)/(g))=m_(water) \\ m_(water)=25.9g \\ \end{gathered}

Resolution number 2 (image):

Finally, the mass of water is 25.9g.

Can somebody help me solve this ? I dont get how to do it-example-1
Can somebody help me solve this ? I dont get how to do it-example-2
User Vitali Tchalov
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