The specific heat capacity of water is 4.184 J/(g·ºC). How much thermal energy is required to change the temperature of 700.0 g of water from 25.6ºC to 75.4ºC?

145854.24J

Explanation:

Given parameters:

Specific heat capacity of water = 4.184J/g°C

Mass of the water  = 700g

Initial temperature  = 25.6°C

Final temperature = 75.4°C

Unknown:

Thermal energy  = ?

Solution:

To solve this problem, we use the expression below;

 H  = m x c x Ф

H is quantity of heat

m is the mass

c is the specific heat capacity

Ф is the temperature change

  H  = 700 x 4.184 x (75.4 - 25.6)  = 145854.24J

  1.the balanced   chemical equation is as below

cu +   2 ag(no)₃ → cu(no₃)₂   +2 ag

2.the   much silver   produced   is   50.9 g

step 1: find the   moles of cu

moles =   mass÷   molar mass

  from periodic table the molar mass of cu = 63.5 g/mol

moles is therefore = 15.00 g÷ 63.5 g/mol = 0.236   moles

step 2: use the mole ratio to determine the   moles of ag

from equation above   cu: ag   is 1: 2

therefore the moles of ag   =0.236   moles   x 2/1 =0.472   moles

step 3: find the mass   of ag

mass = moles x molar mass

from periodic table   the molar mass of ag =107.87 g/mol

mass   = 0.472   moles x 107.87 g/mol = 50.9 g

3.   the   much   silver   collected worth is   1.797 oz

  convert   50.9 g   to oz

that is   1 gram = 0.0353 oz

          50.9 grams =?   oz

by cross multiplication

={(50.9 grams x 0.0353 oz) / 1   gram}   =1.797 oz