Suppose you wanted to heat a mug of water (178 ml) from room temperature 10 °c to 52 °c to make a cup of tea. how much energy (in units of joules) would you need from your microwave? (cwater=4.184 j/g˚c)

Q = 31279.6  j

Explanation:

Given data:

Mass = 178 mL

Initial temperature = 10°C

Final temperature = 52°C

Specific heat capacity = 4.184 j/g.°C

Heat absorbed = ?

Solution:

First of all we will convert the mL to g.

178 mL×1 L/1000 mL = 0.178 L

1 L = 1000 g

0.178 × 1000 = 178 g

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = T2 - T1

ΔT =  52°C - 10°C

ΔT = 42°C

Q = m.c. ΔT

Q = 178 g× 4.184 J/g.°C ×42°C

Q = 31279.6  j

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

warm front forms when a moist, warm air mass slides up and over a cold air mass. as the warm air mass rises, it condenses into a broad area of clouds. a warm front brings gentle rain or light snow, followed by warmer, milder weather.

hope i !