unit2. stoichiometry

I have silicon (at the picture) element in my hands. What the relative mass of this atom?

• 14

• 28

• 42

• I dont know

Darrell is a physicist. One day, he want to know what happen when an UV-light is directly shoot toward isotope manganese-55. As a result of this experiment, he got a new atom called manganese-56. What is the relative mass of isotope manganese-55?

• 55

• 56

• 57

• 58

Calculate the relative molecular mass of CaO!

• 16

• 40

• 56

• 112

Calculate the relative molecular mass of sodium hydroxide!

• 1

• 16

• 23

• 40

Calculate the number of moles in 11 grams of Boron atoms

• 0,1

• 1

• 2

• 2,5

Calculate the number of moles in 46 grams of sodium atoms

• 0,1

• 0,5

• 1

• 2

Calculate the mass of 0,2 mol of iodine molecules

• 12,7 grams

• 25,4 grams

• 50,8 grams

• 101,6 grams

Calculate the mass of 10 mol of phosphor atoms

• 15

• 31

• 150

• 310

Calculate the number of moles in 120 grams of sodium hydroxide (NaOH)

• 120 moles

• 6 moles

• 3 moles

• 1 mole

Calculate the number of moles in 112 grams of carbon monoxide (CO)

• 4

• 5

• 7

• 9