Daily Science April 13

What is STP?Use the reaction shown below to answer the

questions: CO + NO N2 + CO2

Balance the equationIf 42.7 g of CO is reacted completely at STP

what volume of N2 gas will be produced?

PG. 103

Energy and chemical change

Energy

The ability to do workEnergy is conservedEnergy stored in a substance because of its

composition- chemical potential energyMost energy is released in heatHeat flows from warmer to cooler; symbol- q

Measuring heat

Metric system- calorieCalorie- the energy required to raise the

temp of 1g of pure water, 1 oCSI unit- joule1 J = 0.2390 cal1 cal= 4.184 J

Specific heat

The amount of energy required to raise the temperature of 1g of that substance by 1 degree C.

Unique to a substance, symbol - cWater- 4.184 J/ (g x oC) gold is only 0.129Mass and temp affect the heat absorbed and

releasedq = c x m x ΔT

Example

If the temperature of 34.4 g of ethanol increases from 25.0 oC to 78.8 oC, how much heat has been absorbed by the ethanol (c= 2.44 J/ (g x oC)?

A 155 g sample of an unknown substance was heated from 25.0 C to 40.0 C. The substance absorbed 5696 J of energy. What is the specific heat of the substance?