The temperature of a sample of water increases from 30.0 degrees C to 40.0 degrees C as 6540 joules of heat are added. What is the mass of the sample of water?

 166 g

Explanation: q = mC∆T

q = heat = 6940 J

m = mass = ?

C = specific heat of water = 4.184 J/g/deg

∆T = change in temperature = 40.0 - 30.0 = 10.0ºC

6940 J = (m)(4.184J/g/deg)(10 deg)

m = 165.9 g = 166 g

166 g

Explanation:

The equation of specific heat capacity is:

ΔE = mcΔtheta

ΔE = 6540J

c = 4200J/kg°C

Δtheta = 40 - 30 = 10

6540 = m × 4200 × 10

6540 = m × 42000

6540 ÷ 42000 = m

m = 0.15571428...

m = 0.166 kg

m = 166 g

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.