Flashcards in HChem Test Chapter 17 Deck (40):

1

## When solving an equilibrium equation (think lab) make sure to...

### Make the side losing the heat negative (make sure answer makes sense

2

## What is the equation to find Qwater

### Mass * 4.184 * delta T

3

## What is the equation to solve for an equilibrium with a metal

### Mass(m)*Cp(m)*delta T(m)=Mass(w)*4.184*deltaT(w)

4

## Heat lost by metal=

### Heat gained by water (make -)

5

## When solving an equation, make sure your units ______

### Agree (kJ, mole, Kelvin for Gibbs)

6

##
When doing heat of formation, make sure that the thing being combusted has a coefficient of ____

These are _________

###
1

Combustion

7

## What is the typical combustion equation

### __+O2--->CO2+H2)

8

## What is Hess's Law

### Regardless of the multiple stages or steps of a reaction, the total enthalpy change for the reaction is the sum of all changes

9

## What is the summation equation

###
Sum of all products' heat of formation-sum of all the reactants' heat of formation

(Multiply by coefficients)

10

## If you are asked to calculate the heat of combustion for butane for a specific compound, make that compound's coefficient ____

###
1

(Don't do this is asked to find the heat of reaction for the entire process)

11

##
If energy is being added on product side, the reaction is _____

If energy is being added on reactant side, the reaction is _____

###
Exothermic

Endothermic

12

## Positive delta S means _______

### More disorder

13

## If something needs a continuous energy supply, it is most likely ____

### Endothermic

14

## An ____ reaction produces energy as it proceeds

### Exothermic

15

## What is the "direction" or trend most chemical reactions move toward in terms of energy and disorder

### Lower energy, higher disorder

16

##
Delta H stands for ___

Delta S stands for ___

Delta G stands for __

###
Enthalpy

Entropy

Gibbs

17

## What is the formula for Gibbs

###
Delta G=delta H-(T*deltaS)

T must be in kelvin

18

## -delta G is ____

### Spontaneous

19

## If a reaction is spontaneous it does not need _____ help

### Outside (catalyst)

20

## The heat content of the activated complex of any reaction is the ___ to the _____

### Bottom, top

21

## The heat content of anything (reactants, products, AC) is ____

### How talk it is (y axis)

22

## Name 4 things that will speed up or slow down a chemical reaction

### Concentration, temperature, catalyst, surface area

23

## When drawing a graph, label the _____ and give it a ____

### Axes, title

24

## - heat is equal to __________

### Heat released (you can say either/or)

25

## When finding a limited reactant, what do you do

###
Go from grams of the reactant to grams of the product

Whichever is less is limiting reactant

26

## When doing dimensional analysis, remember that if the element is diatomic, factor that into ____

### Molar mass

27

## qH2O=___

### -qrxn

28

## What is the Hf value for elements

### 0 (they are naturally occurring and no heat is absorbed)

29

## Delta H =

### qrxn/moles

30

## When doing enthalpy calorimetry and finding final temperature, what do you do

### Set enthalpy =qrxn/moles, find moles, cross multiply to find qrxn, turn it negative and set equal to mass, Cp, and Tf-Ti

31

## 1.00 ml of water=

### 1.00 g of water

32

## When doing specific heat equation, put temp in ___

### C

33

## What is the second law of thermodynamics

### Changes in the universe tend towards a state of greater disorder

34

## More moles to less moles is __ delta S

### -

35

## The tendency for all reactions is to have __delta H and __ delta S

### -,+

36

## The equation for the delta Hf of N2O is:

### N2(g)+3/2O2(g)--->N2O3(g)

37

## Disorder is ___ delta S

### +

38

## The equation for Hf is not _______, but you write the equation for one mole of the compound asked

### Summation

39

## The equation for the delta Hf of any molecule always contains either __ or ___

### 02 or H2

40