Isotopes of an element have a different number of...

How many isotopes are shown in this mass spectrum?

What is the relative atomic mass for this element?

The combustion of 0.202 g of an organic compound produces 0.361 g of CO₂ and 0.147 g of water. Determine the molecular formula of the compound if it consists of C, H and O and has the molar mass of 148 g/mol. (Mr CO2 = 44 g/mol, Mr H2O = 18 g/mol)

What is the mass of 0.75 moles of (NH₄)₃PO₄? (Molar mass: N = 14 g/mol, P = 31 g/mol, O =16 g/mol)

What is the molarity of a 0.5L sample of a solution that contains 60.0 g of sodium hydroxide (NaOH)? (Molar mass: Na = 23 g/mol, O = 16 g/mol, H = 1 g/mol)

How many grams of AgNO₃ (MM = 169.9 g/mol) are needed to prepare 0.125M solution in 250 mL of water?

Suppose a hydrochloric acid solution contains 36 g of HCl and 64 g of H₂O. What is the mole fraction of HCl? (Molar mass : H = 1 g/mol, Cl = 35.5 g/mol, O = 16 g/mol)

What is the molality of a solution in which 3.0 moles of NaCl is dissolved in 1.5 Kg of water?

How much solvent is needed to create 0.05 m solution when you have 0.50 moles?

If I have 1500 g of solvent, how many moles would be present in a 3 m solution?

What is a limiting reactant?

Calculate the theoretical yield if given the actual yield and percent yield are 51.4g and 77.0% respectively.

4NH₃ + 5O₂ → 4NO + 6H₂O

Based on reaction above, oxygen is a limiting reactant. Calculate the mass of NO formed if the volume of oxygen reacted is 1.26 L at STP.

(Molar mass: N = 14 g/mol, H= 1 g/mol, O =16 g/mol)

(Molar volume at STP : 22.4 dm3/mol)

Fe + S --> FeS

If 7.62g Fe react with 8.67g S, what is the limiting reactant? (Molar mass: Fe = 55.9 g/mol, S = 32.1 g/mol)

CH₄ + 2H₂O → CO₂ + 4H₂

How many grams of CH₄ needed to react in order produce 0.45 g of H₂ gas with percentage yield of 85%? (Molar mass : C = 12 g/mol, H = 1 g/mol, O = 16 g/mol)