need help answering questions - Research Paper 101

What is the empirical formula of a compound composed of 25.1 g of potassium (K) and 5.14 g of oxygen (O)? Insert subscripts as needed.

empirical formula:

A 17.02 g sample of a compound contains 5.43 g of potassium, K, 4.92 g of chlorine, Cl, and oxygen, O. Calculate the empirical formula.

Insert subscripts as needed.

Empirical formula:

KClO

A 9.32 g sample of a compound contains 5.95 g of iron, Fe, 1.10 g of phosphorus, P, and oxygen, O. Calculate the empirical formula for the compound.

empirical formula:

Determine the empirical formula for a compound that contains 58.8% C, 9.8% H, and 31.4% S by mass.

empirical formula:

Determine the empirical formula for a compound that is 62.1% C, 10.4% H, and 27.5% O by mass.

empirical formula:

What is the empirical formula of a compound composed of 3.25% hydrogen (H), 19.36% carbon (C), and 77.39% oxygen (O)by mass?

Insert subscripts as needed.

empirical formula:

HCO

hw 8

For the chemical reaction shown,

2H2O2(l)+N2H4(l)⟶4H2O(g)+N2(g)

_{}^{}_{}^{}_{}^{}_{}^{}_{}^{}_{}^{}

determine how many grams of N2 are produced from the reaction of 9.97 g of H2O2 and 6.35 g of N2H4.

N2 produced:

When heated, KClO3 decomposes into KCl and O2.

2KClO3⟶2KCl+3O2

If this reaction produced 89.1 g KCl, how many grams of O2 were produced?

mass:

g O2

When 0.540 g of sodium metal is added to an excess of hydrochloric acid, 5610 J of heat are produced. What is the enthalpy of the reaction as written?

2Na(s)+2HCl(aq)⟶2NaCl(aq)+H2(g)

Enthalpy of reaction:

When methanol, CH3OH, is burned in the presence of oxygen gas, O2, a large amount of heat energy is released, as shown in the combustion reaction.

CH3OH(g)+32O2(g)⟶CO2(g)+2H2O(l)Δ =−764 kJ

Based on the balanced thermochemical reaction, how much heat is produced when 33.6 g of methanol reacts with 52.1 gof oxygen?

heat:

When calcium carbonate is added to hydrochloric acid, calcium chloride, carbon dioxide, and water are produced.

CaCO3(s)+2HCl(aq)⟶CaCl2(aq)+H2O(l)+CO2(g)

How many grams of calcium chloride will be produced when 30.0 g of calcium carbonate is combined with 12.0 g of hydrochloric acid?

mass of CaCl2:

Which reactant is in excess?

HClCaCO3

How many grams of the excess reactant will remain after the reaction is complete?

mass of excess reactant:

Nitrogen and hydrogen combine at a high temperature, in the presence of a catalyst, to produce ammonia.

N2(g)+3H2(g)⟶2NH3(g)

Assume 0.200 mol N2 and 0.633 mol H2 are present initially.

After complete reaction, how many moles of ammonia are produced?

NH3:

mol

How many moles of H2

_{}^{}

remain?

H2:

mol

How many moles of N2

_{}^{}

remain?

N2:

mol

What is the limiting reactant?

hydrogen

nitrogen