Question

How much heat must be added to heat 0.750 g of water from 20.0 degrees * C to 40.0C (Remember, Q=C*m* Delta T) The specific heat of water is joule/gram.

Answer 1

D. 62.8 J

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right

Chemistry

Thermodynamics

Specific Heat Formula: q = mcΔT

• q is heat (in joules)
• m is mass (in grams)
• c is specific heat (in J/g °C or J/g K)
• ΔT is change in temperature, final minus initial (°C or K)

Step-by-step explanation:

Step 1: Define

[Given] m = 0.750 g

[Given] c = 4.186 J/g °C

[Given] ΔT = 40.0 °C - 20.0 °C = 20.0 °C

[Solve] q

Step 2: Solve

1. Substitute in variables [Specific Heat Formula]: q = (0.750 g)(4.186 J/g °C)(20.0 °C)
2. [Heat] Multiply [Cancel out units]: q = 62.79 J

Step 3: Check

Follow sig fig rules and round. We are given 3 sig figs.

62.79 J ≈ 62.8 J