1. THANKSGIVING H.W. ANSWERS
K2Cr2O7 K
2 mol x
39.00 g/mol =
78.00 g Cr
g/mol= g O
7mol x
15.99 g/mol= g
1a) Molar mass (GFM) = g/mol
1b) 2 moles of K are in I mole of
K2Cr2O7
1c)How many moles are in the grams of ( )
150.0 g 1 ( )
293 g
1 mol
=0.5102mol K2Cr2O7
K2Cr2O7

2. ( ) ( ) ( ) ( ) ( ) ( ) 1c) How many particles are in the 150.00 g
1 mol ( )
1 mol
6.02 x 1023
particles
= 3.07 x 1023 molecules K2Cr2O7
1d) What is the mass of x 1023 particles of
K2Cr2O7 ( ) ( ) ( )
12.01 x 1023 particles
1 mol
293 g
= 3.07 x 1023 molecules K2Cr2O7 1
6.02 x 1023
particles
1 mol

3. ( ) ( ) ( ) ( ) ( ) ( ) 1 mol 17 g 51.0 g NH3 1 1 mol
2a-b)what is the mass of x 1023 particles of NH3 (gfm=17g/mol) ( ) ( ) ( )
18.06 x 1023
PARTICLES
1 mol
17 g
51.0 g NH3 1
6.02 x 1023
PARTICLES
1 mol
2c) What is the mass of x 1023 particles of
K2Cr2O7 ( )
18.06 x 1023 particles 1 ( ) ( )
1 mol
22.4L
=67.2 L NH3
6.02 x 1023
particles
1 mol

4. ( ) ( ) ( ) ( ) Pb(NO3)2 Molar mass (GFM) = 331.152 g/mol Pb 1 mol x
3)How many grams of lead nitrate = the moles of grams of ( )
150.0 g 1 ( )
293 g
1 mol
K2Cr2O7 ?
= mol K2Cr2O7 ( ) ( ) g
mol
g= Pb(NO3)2 1
1 mol
Pb(NO3)2 Pb
1 mol x
207.2 g/mol = g N
2 mol x
g/mol= g O
6mol x
15.99 g/mol=
95.94 g
Molar mass (GFM) = g/mol