AC chemistry Unit 4/5 Chemical Quantities and Reactions and Stoichometry Test

How many moles of magnesium are in 3.01 x 1022 atoms of magnesium?

.050 mol

Chemical symbol for Liquid, Solid, gas, and Dissolved in water

L S G Aq

Calculate the molar mass of Mn2O7, an oxide of manganese.

Molar mass = 221.88 g/mol

Which products would result from the double replacement reaction between MgCl2(aq) and Na2CO3(aq)?

NaCl(aq) and MgCO3(s)

Stoichimetry

The quantitative relationship between amounts (usually moles) of reactants and products in a chemical reaction.

Synthesis

Two or more elements added together to create a compound. A+B —>AB

You can only use 1 mole = 22.4 L when.....

When we are finding gases

Empirical formula

a chemical formula showing the ratio of elements in a compound rather than the total number of atoms

STP (standard temperature and pressure)

conditions of 0.00°C and 1 atm pressure

Conversion Factor Formula

new amount needed ÷ amount on recipe = conversion factor

Single replacement

one element replaces another element in a compound AB + C—> A + BC

Mole

the SI base unit used to measure the amount of a substance

Percent composition

the percent by mass of each element in a compound

limiting reactant (reagent)

the reactant that is completely consumed when a reaction is run to completion

Predict the products of the following combustion reactions, and balance each reaction equation C5H12 + 8O2—> 2C2H2 + 5O2—>

1. 5CO2 + 6H2O 2. 4CO2 +2H2O

Calculate the molar mass of adrenaline (C9H13NO3), a hormone responsible for regulating heart rate and other functions of the sympathetic nervous system.

Molar mass = 183.20 g/mol

How many moles of calcium, Ca, are in 5.00g of calcium?

0.125

What is the mass in grams of 0.0135 mol of the element sodium, Na?

0.310 g Na

If you have 9.0g of aluminum, Al, how many moles of aluminum do you have?

0.33

How many moles of O2 are in 26.3 liters of STP?

0.825L

For determining STP what formula do you uses?

1 mole = 22.4 L

Identify each of the reactions below as synthesis (S), decomposition (D), single replacement (SR) or double replacement (DR). 1. K2O(s) + H2O(l)—> 2KOH(aq) 2.2MgCl2 (aq) +Na2CO3(aq)—> 2NaCl(aq) + MgCO3 3. 2Al2O3(s)—> 4Al(s) + 3O2(g) 4. Cu(NO3)2(aq) +Zn(s)—> Cu(s) + Zn(NO3)2(aq) 5. 2C8H18 (g) + 25O2(g)—> 16CO2(g) + 18H2O (g)

1. Synthesis 2. Double replacement 3. Decomposition 4. Single replacement 5. Combustion

How many atoms of aluminum, Al, are in 2.75 mol of aluminum?

1.66 x 10^24 atoms Al

how many moles of gold, Au, are in 3.60x 10-5g of gold?

1.82 x 10-7

How many atoms are in 5.00g of carbon?

2.50x1023

The molar mass PdBr2 is _______ The molar mass of CuBr2 is _______ The molar mass of BeBr2 _____ The molar mass of CaBr2 is ______

266.22 g/mol 223.35 g/mol 168.81 g/mol 199.88 g/mol

Sodium metal combines with chlorine gas to yield sodium chloride.

2NaCl

Vanadium II oxide with iron III results in the formation of vanadium V oxide and Iron II oxide. (Write the correct balanced equation with states of Matter).

2VO + 3Fe2O3 —-> V2O5 + 6FeO

Write the balanced equation for the reaction that occurs when iron (II) chloride is mixed with sodium phosphate forming iron (II) phosphate and sodium chloride.

3 FeCl2 + 2 Na3PO4 —> Fe3(PO4)2 + 6 NaCl

What is the volume, in liters, of 1.35 mol of chlorine gas at STP？

30.24L

Calculate the number of molecules in 7.00 moles H2S.

4.21x1024 H2S molecules

If you are given 67.5 grams of NaHCO3, how many formula units of NaHCO3 would you have?

4.84x1023 formula units

how many liters are in 65.3g of chlorine gas at STP?

41.22L

What is the molar mass of Fe, Vanadium, and Al2O3?

55.933, 50.942 2(26.982) + 3(15.918) = 101.961

A sample of propane, C3H8 C3H8, contains 15.9 moles of carbon atoms. How many total moles of atoms does the sample contain?

58.3 moles

Calculate the number of moles of Cl atoms in 1.81×1024 formula units of magnesium chloride, MgCl2.

6.00 moles of Cl

Decomposition

A chemical reaction that breaks down compounds into simpler products. AB—>A + B

Which of the following is a combination reaction? A. CaCl2(aq) + Na2SO4(aq) —> CaSO4 (s) + 2NaCl(aq) C. N2(g) + O2(g) —> 2NO(g) D. AgNO3(aq) +NaCl(aq) —> AgCl(s) + NaNO3(aq)

C

The following reaction takes place when an electric current is passed through water. It is an exple of a ______________ reaction.

Decomposition

Which changes are evidence of a chemical reaction? A leaker becomes hot to the touch after two solutions are mixed, Bubbles forming in a shaken water bottle, Ethanol evaporating, a cloudy solution becomes clear upon adding another solution to it, and Bubble formation on chalk added to acid.

Evidence- A leaker becomes hot to the touch after two solutions are mixed, a cloudy solution becomes clear upon adding another solution to it, and Bubble formation on chalk added to acid. Not evidence- Bubbles forming in a shaken water bottle, Ethanol evaporating

mass to mass

Mass A --> Moles A --> Moles B --> Mass B Grams —> moles —> moles —> grams

Grams—>_______ Divide ___________________

Moles Divide grams by molar mass

What can Avogadro's number be used to convert?

Moles and atoms, molecules, or formula units using the following ratios

Calculate the number of moles of aluminum, sulfur, and oxygen atoms in 4.00 moles of Aluminum sulfate, Al2 (SO4)3

Moles of Al, S, O = 8.00, 12.0, 48.0 moles

Calculate the number of moles of magnesium, chlorine, and oxygen atoms in 8.90 moles of magnesium perchlorate, Mg (ClO4)2

Moles of Mg, Cl, O = 8.90, 17.8, 71.2 moles

Avogadro's number

Number of items in one mole and has a value of 6.02 x 1023

What does Combination mean

Synthesis

In a lab, silver nitrate,AgNO3 AgNO3, is dissolved in water until no solid is observed in the container. Then, a solution of sodium chloride, NaCl NaCl, is added to the container. When you combine these aqueous solutions, there is no noticeable change in temperature; however, a solid precipitates and there is a slight change of color. Which statements about the lab experiment involving silver nitrate and a sodium chloride solution are true? Formation of a solid indicates a chemical reaction occurred, the lack of temperature change indicates a chemical reaction didn't occur, A chemical reaction did occur when the solutions were combined, the initial disappearance of silver nitrate in water indicates a chemical reaction occurred. the initial disappearance of silver nitrate in water indicates a chemical reaction occurred.

True- Formation of a solid indicates a chemical reaction occurred, the lack of temperature change indicates a chemical reaction didn't occur, A chemical reaction did occur when the solutions were combined False-The initial disappearance of silver nitrate in water indicates a chemical reaction occurred and the initial disappearance of silver nitrate in water indicates a chemical reaction occurred.

mole to mole conversions

Use the coefficients from your balanced equation to determine your conversion factor. Be sure your units cancel out so you end up with the correct mole value.

combustion

a chemical reaction that occurs when a substance reacts with oxygen, releasing energy in the form of heat and light hydrocarbon + oxygen --> carbon dioxide + water

Double Replacement

a chemical reaction where two elements in different compounds trade places. AB +CD —> AD + BC