Review Concepts & Practice Problems from CHEM 161

What’s a Molecule?

group of atoms with no charge

What’s a Compound?

make up of 2 or more different atoms held 2gether by bonds

What are Ions?

Atoms with a charge

What is the Chemical Law Mass Conservation?

mass is conserved in a chem reaction

What is Definite proportions law?

Compound always contain same proportion of their components

What is the Constant composition law?

same element commotion no matter the source it’s come from.

What are intensive properties & some examples?

independent of the amount of a substance

• Color, odor, malleability & density

What are extensive properties & some examples?

Dependent on the amount of substance

• mass

• volume

• length

• size

What are examples of Physical Properties?

• Density

• Color

• Metal

• Squid & room temp

• Dissolving

• Precipitation

What are some examples of Chemical Properties?

• Reactions that occur with O2 or H2O

• Rust

• Corroding

• Burning

• Decomposing

What makes something a mixture?

can be separated by physical means

Homogenous VS. Heterogenous Mixture?

mixed in a uniformed fashion VS. mixed in a un-uniformed fashion

From left to right what would the states of matter be?

Solid —> Liquid —> Gas

Precision VS Accuracy

• Closeness of taken/measured values

VS.

• Closeness to a true definite value

What makes the Bolded #s sig figs & what’s the last s.f.?

129

• All Non-zero digits

• 9

What makes the Bolded #s sig figs & what’s the last s.f.?

5007

• Zeros between non-zero digits

• 7

What makes the Bolded #s sig figs & what’s the last s.f.?

1000.0

• Trailing zeros that contain a decimal point

• 0 (after the point)

What makes the Bolded #s sig figs & what’s the last s.f.?

0.000470

• zeros infant of non-zero digits don’t count & there is a zero after a decimal point that would count

• 0

What makes the Bolded #s sig figs & what’s the last s.f.?

0.0025

• zeros before the non-zero digits not counting. Starting of non-zero digits.

• 5

What makes the Bolded #s sig figs & what’s the last s.f.?

100

• trailing zeros in a number that isn’t a decimal

• 1

What makes the Bolded #s sig figs & what’s the last s.f.?

9.8 × 10^6

• 10 & exponent in scientific notation do not count as sig.figs

• .8

What is the # of Sig figs in each #?

1. 250.7

2. 0.00077

3. 4.7 × 10^-5

4. 500.0

5. 0.034000

6. 220

7. 220.

1. 4

2. 2

3. 2

4. 4

5. 5

6. 2

7. 3

What is mega a multiple for & it’s symbol?

10 ^ 6

• M

What is kilo a multiple for & it’s symbol?

10³

• k

What is deci a multiple for & it’s symbol?

10^-1

• d

What is centi a multiple for & it’s symbol?

10^-2

• c

What is milli a multiple for & it’s symbol?

10^- 3

• c

What is micro a multiple for & it’s symbol?

10^-6

• μ

What is nano a multiple for & it’s symbol?

10^-9

• n

What is pico a multiple for & it’s symbol?

10^-12

• p

What is bigger a nanogram or gram?

gram

how many ng are in 8.9?

8.9 × 10^-9 ng

how many km is 1.6 m?

1.6×10³km

as proton number increases what will be required to get a stable nucleus?

more neutrons

one mole of atoms is equivalent to?

the molar mass

What is Molarity? or M

mol of solute/ liter of solution