chp 1 general chem DAT

Question 1

avogadros number

Answer 1

6.022x10^23

Question 2

what is Avogadros number ?

Answer 2

is a measurement of 1 mole ( so C on the period table is 12 g = 12g of c is 6.022x10^23 atoms or moles of C)

Question 3

molecular weight

Answer 3

adding all individual masses of each of the atoms in that molecule

Question 4

balancing chem equations

Answer 4

same amount of elects on each side of the equation

Question 5

combustion reactions

Answer 5

Is a rapid reaction in which hydrocarbon or an alcohol reacts with oxygen the precuts will always be CO2 AND H2O

Question 6

molecular and empirical example glucose

Answer 6

glucose is really C6H12O6 this is the molecular formula but the empirical would be simplified CH2O

Question 7

percent composition

Answer 7

how much of that element is in the compound -
add each molecular mass then divide the mass of element that needs to be calculated by the Total weight and x 100

Question 8

2 ways to ask for percent composition

Answer 8

you are given molecular formula and they ask for a specific element
OR
you are given the mass percent of each element in compound and are asked to determine compounds formula

Question 9

percent comp of nitrogen in morphine C17H19NO3

Answer 9

calc total molec mass of morphine, calc mass of nitrogen , divide mass of nitrogen by total molec weight and x100

Question 10

what is the empirical formula of a compound with 17.3% H and 82.7% C

Answer 10

assume 100g total sample
convert each % into decimal directly so ( 17.g and 83.7 g ) then divide by each element atomic mass. then divide by each elements answer by whichever number was smaller. if the number is not whole then multiply by 2

Question 11

empirical to molecular formula

Answer 11

1. divide molecular weight by the weight of the empirical formula
2. multiply each sub in the empirical formula by the answer in step 1.
   = molecular formula

Question 12

limiting reactants

Answer 12

the reactant that runs out faster. amount of product depends on the amount of limiting reactant

Question 13

product and reactants steps

Answer 13

BCC
balance - convert to moles- use coefficients in the equation to transform moles

Question 14

if question says” excess”

Answer 14

this reactant is Not the limiting reactant

Question 15

to identify the limiting reactant use ..

Answer 15

BCDS
balance
convert everything to moles
divide moles/coeff
smallest one wins

Question 16

theoretical yield

Answer 16

is the amount of product you should get in a given reaction if everything is perfect

Question 17

PY formula

Answer 17

actual / Theo X 100