Flashcards in SAT CHEM Deck (20):

1

## Units of Pressure

### 760 torr = 760mmHg = 1 atm

2

## Units of Energy

### calories (cal) and joules (J)

3

## Breaking bonds _______ energy

### Requires

4

## Forming bonds _______ energy

### Releases

5

## Specific heat def

### The amount of heat to raise the temperature of 1g of a substance by 1 degree Celsuis

6

## q=

###
m (mass )* c (specific heat) * delta T (change in temperature)

*Use Celsius*

7

## Diatomic Elements

###
Oh I Have Nice Closets For Brooms

O I H N Cl F BR

8

## Avogadro's Number (Mole)

### 6.02*10^23

9

## 1 amu

### 1/12 mass of C-12 a.k.a 1g

10

## convert from mass composition to the empirical formula

###
1. convert percent into 100g: 50% = 50g

2. Convert to Moles

3. Divide by smallest mole and round to nearest integer to get ratio

11

## Entropy

###
Measure of disorder

The higher the entropy and the lower the energy the more stable it is

Symbolized by delta S

12

## Enthalpy

###
Direct relationship between enthalpy and energy

Universe like low enthalpy and high entropy

Symbolized by H

When delta H is negative it is exothermic and enthalpy decreases therefore occurs more often

When delta H is positive it is endothermic and enthalpy increases therefore doesn't occur as often

13

## Heat of Formation

###
Symbolized by delta H subscript f

If negative heat is released and vice versa when it is positive

Elements have a heat of formation of 0

14

## Hess's Law

### delta H will be equal to the sum of the enthalpy changes in individual steps whena reaction occurs in more than one step

15

## Gibbs' Free Energy

###
delta G = delta H - T*delta S

Temperature is in Kelvin

When delta G is negative occurs spontaneous in forward reaction

When delta G is positive occurs spontaneous in reverse reaction

When delta G is 0 occurs reached equilibrium

16

## Electrons exist in _________

### Orbitals

17

## Electrons farther away have _________ energy than those closer to the nucleus

### greater

18

## Sub-shells: Number and Shape

###
s: 1 spherical

p: 2 dumbbell

d: 5

f: 7

Any orbital can hold a maximum of 2 electrons

19

## Principle Quantum number (n)

###
Distance from nucleus

Ex: First energy shell: n=1

20