Chemistry Quiz 1

f25

What are some specific conversions?

5280ft = 1mi

2.54cm = 1in

12in = 1ft

1mL =1cm³

60s = 1min

60min = 1hr

24hr = 1 day

365 days = 1yr

What are some metric prefixes?

G = 10⁹

M = 10⁶

K = 10³

h = 10²

da = 10¹

base unit

d = 10^-1

c = 10^-2

m = 10^-3

μ = 10^-6

n = 10^-9

p = 10^-12

What is the freezing and boiling point of ^oF, ^oC, and K?

K: freezes at 273K, boils at 373k

^oF: freezes at 32^oF, boils at 212^oF

⁰C: freezes at 0^oC, boils at 100^oC

What is the temperature conversion equations?

K = ^oC + 273.15

^oF = ^oC(9/5) + 32

What is density?

The ratio of mass to volume

What is density’s equation?

Density = Mass / Volume

Name 3 materials and their density’s

Osmium metal = 22.6 g/mL

Water = 1.00 g/mL

Hydrogen gas = 8.99 × 10⁵ g/mL

What is precision?

Precision is the number of digits/ how well measurements agree with one another

What is accuracy?

Accuracy is how well measurements agree with the accepted value

What are the sigfig rules?

All none zero numbers are significant, all leading zeros are not significant, all trailing zeros after a decimal are significant, all zeros between two sigfigs are significant, and all exact numbers have infinite sigfigs

What do sigfigs look like when you add or subtract?

You use the least number of decimal places

What do sigfigs look like when you divide and multiply?

You use the least number of sigfigs

Chemistry definition

study of matter and associated changes

Matter definition

everything with mass and volume

Composition definition

substances and their amounts in matter

Pure substance definition

Material with constant composition

Element definition

Pure substance that can’t be broke down further by physical or chemical means

Compound definition

Pure substance with more than one element

Atom definition

smallest particle of element that shares same properties

Molecule definition

substance with two or more atoms connected by chemical bond

Ion definition

charged atom or molecule

Mixture definition

contains multiple substances and can be separated by physical means

Draw a line with the following words: low temp, condensation point, melting point, boiling point, increased temp, freezing point

look in notebook

What is a heterogenous mixture?

varying compositions (think water and oil)

What is a homogenous mixture?

Uniform compositions

What are the phases of matter?

solid, liquid, and gas

Define physical properties

Relates to observable properties such as color, mass, volume, and dimensions

Define chemical properties

Relates to reactions/ processes that alters the identites of substances

What is the law of conservation of mass?

Matter cannot be created or destroyed, it can only be converted from one form to another

What is the law of definite composition?

Compounds always contain a fixed ratio of their elements

What is the scientific method?

Observations —→ hypothesis (predictions) —→ experiment (collect data, only change 1 variable at a time) —→ model (theory, law)

Define theory

Describes causes

Define law

Describes consistent observations (mathematics equation typically)

What is this?

It’s the nuclear model of an atom. The red contains neutrons and protons while the green contains only electrons

What is the mass (ama) of a proton?

1.0073 (roughly 1)

What is the mass (ama) of a neutron?

0

What is the mass (ama) of an electron?

roughly zero

Charge of a proton

+1

Charge of a neutron

0

Charge of an electron

-1

What does each thing stand for?

X is the atomic symbol, A is the mass number, Z is the atomic number, and Q is the charge.

How do you calculate mass number?

Protons + neutrons

How do you determine the atomic number?

The number of protons

How do you determine the charge of an element?

Protons - electrons

Is a negative amount of electrons a thing?

No

What is a group

Elements with similar properties in the same column

What is a period?

Rows on the periodic table

Where are the alkali metals?

The first column

Where are the alkaline earth metals?

The second column

Where are the icosagones?

The third tallest column

Where are the crystallogens?

The fourth tallest column

Where are the pnictogens?

The fifth tallest column

Where are the chalcogens?

The sixth tallest column

Where are the halogens?

The seventh tallest column

Where are the noble gases?

The last column

Where are the rare Earth metals?

The two periods at the bottom (rows called periods)

Where are the metals, metalloids, and nonmetals?

Metals on the left side, metalloids are the staircase ( the reds) and the nonmetals are above the staircase

What are some metal traits?

Generally solid at room temperature, good conductors, form cations, malleable, and ductile(can be made into wires)

What are some nonmetal traits?

They vary between solids, gases, and liquids due to being brittle. They form anions and are poor conductors

What is something special about carbon?

It has multiple isotopes in nature (same p⁺ different n⁰)

What is average atomic mass?

A weighted average

What few elements exist alone in nature?

Noble gases, diatonic molecules, and coinage metals

Since few elements exist by themselves in nature, how do other atoms exist?

As compounds. Metals in ores typically

How can you identify if something is ionic?

Metals and nonmetals, typically ions [charged], they’re represented as a formula unit. They have HIGH melting/ boiling points, and they separate into ions in water

How can you identify if something is covalent (molecular)?

Typically just a nonmetal, neutral atoms, represented as molecule, have LOW melting/ boiling points and separate into neutral molecules in water

What does it mean for something to be ionic?

They transfer electrons

What does it mean for something to be covalent (molecular)?

They share electrons

What are the rules for the name and formulas of ionic compounds?

Write the name of metal first, nonmetal second but change the ending to “-ide”. For transition metals and late metals write the charge after metal in parenthesis using roman numerals (EXCEPT FOR Al, Zn, Ag), and polyatomic ions keep their suffix

What is a polyatomic ion?

An ion that has covalent bonding between the parts

What are the three transition metals that you don’t need to list their charges?

Aluminum, zinc, and silver

Hg₂²⁺

Mercury(I)

NH₄⁺

Ammonium

H₃O⁺

Hydronium

OH^-

Hydroxide

O₂^2-

Peroxide

CN^-

Cyanide

SCN^-

Thiocyanate

C₂O₄^2-

Oxalate

C₂H₃O₂^-

Acetate

N₃^-

Azide

NO₃^-

Nitrate

NO₂^-

Nitrite

CO₃^2-

Carbonate

HCO₃^-

Bicarbonate

ClO^-

Hypochlorite

ClO₂^-

Chlorite

ClO₃^-

Chlorate

ClO₄^-

Perchlorate

BrO₃^-

Bromate

IO₃^-

Iodate

CrO₄^2-

Chromate

Cr₂O₇^2-

Dichromate

PO₄^3-

Phosphate

HPO₄^2-

Hydrogen phosphate

H₂PO₄^-

Dihydrogen phosphate

SO₄^2-

Sulfate

HSO₄^-

Bisulfate

SO₃^2-

Sulfite

S₂O₃^2-

Thiosulfate

MnO₄^-

Permanganate