Stoichiometry Practice

1. What mass of K would react to produce 156 g of KCl

2K + Cl₂ --> 2 KCl

• 81.8 g of K

• 82 g of K

• 2.09 g of K

• 80.1 g of K

Tags

NGSS.HS-PS1-7

2. How many moles of Zn will be formed if 32.0 g of Cu is used as a reactant?

2 Cu+ Zn(NO₃)₂--> Zn + 2 Cu(NO₃)

• 0.25 moles Zn

• 0.251 moles Zn

• 0.252 moles Zn

Tags

NGSS.HS-PS1-7

How many grams of Fe are formed form 42 g of Fe(SO₄)

2 Al + 3Fe(SO₄) --> 3 Fe + Al₂(SO₄)₃

• 20.56 g Fe

• 15 g Fe

• 15.4 g Fe

• 16 g Fe

Tags

NGSS.HS-PS1-7

How many moles of Ag₂O are formed form 7.9 g of HCl

Ag₂O + 2 HCl--> 2 AgCl + H₂O

• 0.108 mole Ag₂O

• 0.11 mole Ag₂O

• 0.100 mole Ag₂O

How many moles of CaCl₂ will form from 250 moles Ca(ClO₃)₂

Ca(ClO₃)₂ --> CaCl₂ + 3 O₂

• 750 mole CaCl₂

• 750.mole CaCl₂

• 250 mole CaCl₂

• 250. mole CaCl₂

Tags

NGSS.HS-PS1-7

Significant figures Rule #1

Digits 1-9 are always significant

Select the numbers that have 3 significant figures

• 23 g

• 159 g

• 3 g

• 291 g

Significant figures Rule# 2

Zeros between 2 significant numbers are always significant

Select the answers that represent this rule

• 123 g

• 1,008 g

• 0.304 g

• 4 g

Significant Figures Rule#3

Zeros to the RIGHT of a #1-9 are significant IF!!! a decimal is present

Select the answers that represent this rule

• 230 g

• 0.0023 g

• 23.00 g

• 32.0 g

Significant Figures Rule #4

Zeros to the LEFT of a #1-9 are NOT significant

Select the answers that represent this rule

• 0.00023 g

• 23.00 g

• 23 g

• 0.32 g

Which numbers has 4 significant figures

• 23.0 g

• 0.02300 g

• 2,300 g

• 2,300. g