Ch. 1
How many sig figs are in 0.1230?
4
What is the difference in a cation and anion?
cation: positive charge
anion: negative charge
What is the difference in ionic vs. molecular compounds?
molecular: only nonmetals
ionic: metal and nonmetals
What is Avogadro's number? What does it mean?
6.022 x 1023
It's how many atoms/molecules/ions are in 1 mole of a substance
Balance the chemical equation:
N2(g) + H2(g) → NH3(g)
N2(g) + 3 H2(g) → 2 NH3(g)
What state of matter is water in at it's standard state (25°C)
liquid
standard states are the temperatures of an element at 25°C.
Write these down on your periodic table!
Isotopes have different numbers of ___________.
neutrons
What is the name of Br2O?
(is it molecular or ionic?)
dibromine monoxide
molecular
How many moles of hydrogen are in CH3(OCH3)3?
12
What is a precipitate?
a solid formed in the reaction
A chemist puts equal amounts of hydrogen atoms and fluorine atoms in a container. When they come back later, the atoms have combined to make HF molecules. Is this a chemical or physical change?
Chemical change
Physical changes change the state of matter (solid vs. liquid vs. gad)
Chemical changes change the chemical formula
How many electrons does a neutral atom of Si have?
How many electrons does Si+ have? Si-?
neutral Si: 14
Si+: 13
Si-: 15
What is the name of CO32-?
carbonate
How many molecules of HF are in 4 moles of HF?
2.4 x 1024 atoms
Write a balanced equation for:
Aqueous hydrochloric acid (HCl) reacts with solid iron(II) sulfide to form hydrogen sulfide gas (H2S) and aqueous iron(II) chloride.
2 HCl(aq) + FeS(s) → H2S(g) + FeCl2(aq)
A cube, with an edge length of 3.0 cm, has a mass of 15.4 grams, what is it's density?
1.71 g/cm3
How many protons and neutrons are in an isotope of 102Rh?
protons: 45
neutrons: 57
What is the formula for lead(IV) permanganate?
Pb(MnO4)4
A chemist weighs 33.7 grams of tin. How many moles is this?
0.284 mol
What type of reaction is this?
Ca(ClO3)2(s) → CaCl2(s) + 3O2(g)
decomposition
How many miles are in 6.7 x 105 cm? (1 in = 2.54 cm; 1 mi = 5,280 ft)
4.16 miles
What is the atomic mass of tin, if:
115Sn has a relative abundance of 47% and mass of 114.9 g
120Sn has a relative abundance of 53% and mass of 119.9 g
117.55 grams
What is the name of this acid: H2SO4
Sulfuric acid
Calculate the number of oxygen atoms in a 130.0 g sample of dinitrogen tetroxide (N2O4).
3.403 x 1024 oxygen atoms
Name the 2 types of reactions in:
FeSO4(aq) + PbCl2(aq) → FeCl2(aq) + PbSO4(s)
double replacement, precipitation