Chemistry: Suppose you wanted to heat a mug of water (250 ml) from room temperature 25 c to 100 c to make a cup of tea. how much energy (in units of calories and joules) would you need from your microwave?

it would be 200yrsExplanation:...

Suppose you wanted to heat a mug of water (250 - id2502789250, allyssaharrisooy50au

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04.01.2022

The amount of heat needed by the microwave is 18750 Cal or 78450 J

Explanation:

To calculate the mass of water, we use the equation:

$\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}$

Density of water = 1 g/mL

Volume of water = 250 mL

Putting values in above equation, we get:

$1g/mL=\frac{\text{Mass of water}}{250mL}\\\\\text{Mass of water}=(1g/mL\times 250mL)=250g$

To calculate the amount of heat absorbed, we use the equation:

$q=mc\Delta T$

where,

m = mass of water = 250 g

c = specific heat capacity of water = 1 Cal/g°C

$\Delta T$ = change in temperature = T_2-T_1=100^oC-25^oC=75^oC

Putting values in above equation, we get:

$q=250g\times 1Cal/g.^oC\times 75^oC\\\\q=18750Cal$

Converting the amount of heat absorbed in Joules, we use the conversion factor:

1 Cal = 4.184 J

So, $18750Cal\times \frac{4.184J}{1Cal}=78450J$

Hence, the amount of heat needed by the microwave is 18750 Cal or 78450 J

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