Mid Term 2016

Question 1

Branch of science that deals with the identification of the substance of which matter is composed

Answer 1

Chemistry

Question 2

When going from gram to mol

Answer 2

Find the molar mass and divide the given gram by your molar mass
Ex. 25g Nacl mol. Na= 23
Cl = 35
+__________
58
25g/58m = .43mNaCl

Question 3

Know how to balance an equation

Ex. ___NaO —-> _____Na+_____O2

Answer 3

2NaO—->2Na + O2

Question 4

Scientific theory of the nature of matter, which states that matter is composed of distinct units called atoms

Answer 4

Atomic theory

Question 5

Discovered electrons by experimenting with a crookes, or a cathode ray tube. He demonstrated that cathode Rays were negatively charged

Answer 5

J.J. Thomson

Question 6

Overturned Thomson’s model in 1911 with his well known gold foil experiment that demonstrated the atom has a tiny heavy nucleus

Answer 6

Rutherford

Question 7

1. All matter is made of atoms. 2. Atoms are indivisible and indestructible. 3. Compounds are formed by a combination of 2 or more different kinds of atoms

Answer 7

Dalton’s atomic theory

Question 8

Form when 2 or more atoms share electrons. Two no metals, right of the stairstep. Ex. CO, ClBr

Answer 8

Covalent bonds

Question 9

Density =

Answer 9

M/V , g/ml , solid = g/cm3

Also… M=DxV, V=M/D

Question 10

Percent Composition aka Mass Percent

Answer 10

Composition = Mass of element/Molar mass X 100
Ex.H2O
H=1x2=2
O=16x1=16
\+\_\_\_\_\_\_\_\_\_\_\_
18
H=2/18=.1x100=11%
O=16/18=.88x100=88%

Question 11

Predict the products of these equations and balance them

1. Al + I2 —>
2. CuCl2 + KOH —>

Answer 11

1. 2Al + 3I2 —> 2AlI3

2. CuCl2 + 2KOH —> Cu(OH)2 +2KCl

Question 12

What is the Electron Configuration for…
Ex. Na
Fe

Answer 12

Na = 1s2, 2s2, 2p6, 3s1
Fe = 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d6

Question 13

Measure of the tendency of an atom to attract a bonding pair of electrons

Answer 13

Electronegativity

Question 14

Doesn’t change what the substance is

Answer 14

Physical change

Question 15

A new substance is formed and energy is given off or absorbed

Answer 15

Chemical change

Question 16

What is being reduced and oxidized? What is the RA and OA

1. Cs + Br2 —> 2CsBr
2. 3Mg + N2 —> Mg3N2

Answer 16

1. Cs = Oxidized/Ra Br=Red/Oa

2. Mg= Oxidized/Ra N= Red/Oa

Question 17

How many dog figs are in….

1. 720
2. 8.4 X 10^3 = .8400
3. 20.003
4. 0.00300

Answer 17

1. 2
2. 2
3. 5
4. 3

Question 18

Orbital Notation

1. Be
2. Ca

Answer 18

1. ¡! ¡! ¡ ¡ ¡
2. ¡! ¡! ¡! ¡! ¡! ¡! ¡! ¡! ¡! ¡!

¡Up !down

Question 19

What’s the difference between a reactant and a product

Answer 19

Reactant is on the left side of the —> in a reaction and the product is on the right side

Question 20

Know stoichiometry

Answer 20

He told me there would be one question about it

Question 21

Which of the following has a positive charge? (This is definitely on the exam)

Answer 21

Proton