Chemistry Final
How many moles of aluminum are needed to react completely with 1.2 mol of FeO? 2Al(s)+3FeO(s)------>3Fe(s)+Al2O3(s)
0.8 mol
How many moles of H3PO4 are produced when 71.0g P4O10 reacts completely to form H3PO4?
1.00 mol
How many molecules are 2.10 mol CO2
1.26e24
When iron rusts in air, iron (III) oxide is produced. How many moles of oxygen react with 2.4 mol of iron in the rusting reaction? 4Fe(s)+3O2(g)------>2Fe2O3(s)
1.8 mol
What is the volume, in liters, of 0.500 mol of C3H8 gas at STP?
11.2 L
What is the mass of oxygen in 250g of sulfric acid, H2SO4?
160g
In the reaction 2CO(g)+O2(g)----->2CO2(g), what is the ratio of moles of oxygen used to moles of CO2 produced?
1:2
The equation below shows the decomposition of lead nitrate. How many grams of oxygen are produced when 11.5g NO2 is formed? 2Pb(NO3)2(s)----->2PbO(s)+4NO2(g)+O2(g)
2.00 g
What is the percent composition of chromium in BaCrO4?
20.5%
If 1 egg and ⅓ cup of oil are needed for each bag of brownie mix, how many bags of brownie mix do you need if you want to use up all 3 eggs and 1 cup of oil?
3
How many hydrogen atoms are in 5 moleciles of isopropyl alcohol, C3H70?
35
What is the number of moles of beryllium atoms in 36g of Be?
4.0 mol
How many grams of H3PO4 are produced when 10.0 moles of water react with an excess of P4O10? P4O10(s)+6H2O(l)-----> 4H3PO4(aq)
653g
How many moles of tungsten atoms are in 4.8e25 atoms of tungsten
8.0e1
Which of the following is true about the reaction shown below? C5H12(l)+8O2(g)------>5CO2(g)+6H2O(g)
9 moles of reactants chemically change into 11 moles of product
What is themolar mass of (NH4)2CO3?
96g
What is the concentration of a solution?
A measure of the amount of solute in a specified quantity of solvent
Which of the following usually makes a substance dissolve faster in a solvent?
Agitating the solution
The ratio of carbon atoms to hydrogen atoms to oxygen atoms in a molecule of dicyclohexyl maleate is 4 to 6 to 1. What is its molecular formula if its molar mass is 280 G?
C16H24O4
What is the empirical formula of a substance that is 53.5% C, 15.5% H, and 31.1% N by weight?
C2H8N
Which of the following compounds have the same empirical formula?
C7H14 and C10H20
Which of the following substances is an electrolytle
CCl4
Using a table that lists standard heats of formation, you can calculate the change in enthalpy for a given chemical reaction. The change in enthalpy is equal to
Delta H of the products munis delta H of reactants
The lowest whole-number ratio of the elements in a compound is called the
Empirical formula
A process that absorbs heat is a(n)
Endothermic proceess
Which of these phase changes is an endothermic process?
Evaporation
The volume of one mole of a substance is 22.4L at STP for all
Gases
Which statement correctly describes the energy of the chemical bonds of the reactants in an ecothermic reaction?
Geater than the enrgy stored in the bonds of the products
The molar mass of C7H16 and the molar mass of CaCO3 contain approximately the same number of
Grams
How is thermal energy transferred between two objects that are at different temperatures?
Heat flows from the warmer object to the cooler object until they reach the same temperature
The bonds between adjacent water molecules are called
Hydrogen bonds
What type of compound is always an electrolyte?
Ionic
In a chemical reaction, the mass of the products
Is equal to the mass of the reactants
Which of these statements correctly describes Hess's law of heat summation?
It is used to calculate delta H for complicated chemical reactions
The units of specific heat are
J/g-K or J/g-C
When two substances react to form products, the reactant which is used up is called the
Limiting reagent
The mass of amole of NaCl is the
Molar mass
Avogadro's number of representatice particles is equal to one
Mole
Combining aqueous solutions of BaI2 and Na2SO4 affords a precipitate of BaSO4. Which ion(s) is/are spectator ions in the reaction?
Na and I
When aqueous solutions of __________ are mixed, a precipitate forms.
NiBr2 and AgNO3
A net ionic equation
Shows only those paticles involved in the reaction
The symbol delta Hf
Standard heat of formation for a compound
The calculation of quanities in chemical equations is called
Stoichiometry
Which of the following is true about limiting and excess reagents?
The amount of products obtained is determined by the limiting reagent
What does the symbol Delta H stand for?
The heat of reaction for a chemical reaction
Which atom in a water molecule has the greatest electronegativity?
The oxygen atom
In a double replacement reaction,
The reactants are generally two ionic compounds in aqueous solution
What do you know about a chemical reaction if the value of delta H is positive?
The reaction is endothermic
When an equation is used to calculate the amount of product that will form during a reaction, then the value obtained is called the
Theoretical yield
How do calories and joules differ from one another?
They are two different units that measure amounts of energy
Which comound is insoluble in water?
ZnS
