Sig Figs
True or False all nonzero digits are significant
What is true? (123- has 3 sig figs, 123456- has 6 sigfigs)
When naming an ionic compound what comes first the positive (cation) or negative (aNion)?
What is cation comes first?
What is the formula for beryllium chloride?
What is BeCl2?
Be +2, Cl -1 , cross over because has to be neutral BeCl2
CO2 + 2LiOH --> Li2CO3 + H2O
How many moles of lithium hydroxide are required to react with 20 mol of CO2?
What is 40 mol LiOH?
20 mol CO2 (2 LiOH/ 1 CO2)
Four main types of chemical reactions?
Synthesis, Decomposition, Single Replacement & Double Replacment
How many significant figures in 1230004?
What is 7? (sandwiched zeros are significant)
When naming an ionic compound which suffix is changed and to what?
What is the negatively charged anion changes to ide?
What is BrF5?
no prefix on first means one, penta means 5
Mg + 2HCl --> MgCl2 + H2 What mass of hydrochloric acid (MM=36.5 g/mol) is needed to react with 2.50 moles of magnesium?
2.5 mol Mg (2 mol HCl/ 1 mol Mg) (36.5 g HCl/ 1 mol HCl)
What are the 4 signs of a chemical reaction?
What is color change, formation of a solid (precipitate), formation of a gas, & change in temperature
Pick the number with 4 significant figures
a. 1230 , b.1230. , c. 1230.0, d.1230.00
What is B?
a)3, b)4, c)5, d)6
Name the compound NH₄NO₃
What is ammonium nitrate?
What is the formula for Hydrosulfuric Acid?
Prefix hydro means its binary (only 2 elements) hydrogen and sulfur
H+1, S-2 can cross over like an ionic compound
(acids are molecular (or covalent) but dissociate like ionic compounds so can do the formula like an ionic compound)
Hydrogen and oxygen gases react under a specific set of conditions to produce water. How many moles of oxygen would be required to produce 5.0 moles of water?
What is 2.5 mol O2?
O2 +2H2 --> 2H2O (both diatomic)
5.0 mol H2O ( 1 mol O2/ 2 mol H2O) = 2.5 mol O2
Properties of an incomplete combustion?
Carbon Monoxide is one of the products
Which number/s only has one significant figure
a)0.00010
b)1000
C)1000.0
d)0.000001
What is b & d
a) 2 SF
c)5 SF
Name both of the compounds CBr4 & N2O
Bonus +200 Name all of the prefixes (1-10) used in covalent compound
What is carbon tetrabromide & what is dinitrogen monoxide?
- don't use the prefix mono on the first element, otherwise use prefixes
mono,di,tri, tetra, penta, hexa, hepta, octa, nona, deca
What is the formula for magnesium phosphate?
Sodium and chlorine react to produce sodium chloride (table salt; MM=58.5 g/mol). Determine the amount of product that can be produced from 24.7 g of sodium and excess chlorine.
What is 62 g NaCl?
2 Na + Cl2 --> 2NaCl (b/c Cl is diatomic)
24.7 g NaCl (1 mole Na / 23 g) (2 mole NaCl / 2 mole Na) (58g / 1 mole NaCl) = 62g NaCl
Solute vs. solvent?
Solute: what dissolves in solution
Solvent: the solution doing the dissolving
What are the rules for multiplying/dividing with sig figs?
What are the rules for adding / subtraction with sig figs?
Multiplication and Division:
•You keep the least number of sig figs
•weakest link
Addition and Subtraction
•Use the smallest number of the decimal place
• left most sig fig
Name the hydrate (water attached in a lattice)
+100 if you correctly use a Roman numeral
CoCl2 *6H2O
What is Cobalt (II) Chloride Hexahydrate?
Name like an ionic compound first half, (II) comes from the fact that cobalt is a transition metal so can have multiple charges in this case its +2 because Cl is -1 but we have 2 of them. Use prefix for how many waters and add hydrate to the end
What is the formula for nitric acid, what is the formula for nitrous acid?
Nitric- HNO3 (nitrate ate--->ic)
Nitrous Acid- HNO2 (Nitrite ite-->ous)
acids formula like ionic compounds
This questions is worth 1000 points! SURPRISE! Chlorine gas reacts with potassium bromide to produce potassium chloride and bromine gas. How many grams of potassium chloride can be produced from 300. g each of chlorine and potassium bromide?
What is 188 g KCl?
Cl2 + 2KBr --> 2 KCl + Br2
Cl2 (71 g/mol ) KBr (119 g/ mol)
4.2 mole Cl2, 2.5 mole KBr
Divide by Coefficent to see LR , LR = KCl
2.5 mol KBr means= 2.5 mol KCl (74.55 g/ 1 mol KCl)
List all the diatomic molecules
HOFBrINCl