i need help for chemistry plus i need the steps please help!!

Question

57.0 calories are added to a lead block. if the temperature of the lead increases from 53 f to 79 f. what must the mass in grams of the lead block? the specific heat of lead is 0.128 j (g C)

Answer 1

Thermodynamics

The relationship you need is q = mcΔT

where q is heat (in cal or Joules), m is mass (in g), c is specific heat, and ΔT is change in temp (in °C or K)

You are given: q = 57.0 cal You are asked for: m = ? (in g)

T_initial = 53°F

T_final = 79°F

c = 0.128 ^J/_(g•°C)

You must first do some conversions so that your units match

convert q value from cal to Joules using conversion factor 1 cal = 4.184 Joule

q = 57.0 cal • (^{4.184 J} / _{1 cal)} = 238 J

convert T from °F to °C using the relationship: (°F − 32) × 5/9 = °C

T_initial = (53°F – 32) x 5/9 = 12°C

T_final = (79°F – 32) x 5/9 = 26°C

Calculate ΔT using ΔT = T_final – T_initial = 26°C – 12°C = 14°C

Now you are ready to rearrange the equation and solve:

q = mcΔT, rearrange to solve for m by dividing each side by cΔT

m = ^q / _cΔT

m = ^{238 J} / _{(0.128 J/(g•°C) • 14°C)} = 133 g