Me i beg you i really need !
which contains a greater number of atoms, a mole of silver or a mole of gold?

a mole of silver.
a mole of gold.
they both contain the same number of atoms.
the answer cannot be determined without knowing the molar mass of each element.

the percent composition of elements in a compound is determined from the compound's chemical formula by dividing the total mass of an element present in the formula by the molar mass of the compound.

true
false

one way to determine the empirical formula of a compound involves using the percent composition of the compound.

true
false

in the equation, 2h2 + o2 > 2h2o, which substance(s) are the reactant(s)?

h2
o2
h2o
h2 and o2

in a chemical equation for a reaction, the arrow sign > means "yields" or "produces."

true
false

what type of reaction is represented by the following chemical equation? ch4 + 2o2 > co2 + 2h2o + heat/light

double replacement
single replacement
combustion
decomposition

what is produced during any combustion reaction?

water and energy
oxygen, water, and energy
one or more oxide compounds and energy
carbon dioxide, oxygen, and energy

in the reaction fe2o3 + 3co > 2fe + 3co2, 10 moles of solid iron and 15 moles of carbon dioxide are produced from 5 moles of iron (iii) oxide and 15 moles of carbon monoxide (co). what is the mole ratio of carbon monoxide to solid iron?

15: 10
5: 10
3: 2
2: 1

solid ammonium nitrate (nh4no3) reacts, over time, to form nitrogen, oxygen, and water gases. this is a synthesis reaction.

true
false

what is the mole ratio of oxygen to propane (c3h8) in the following equation? c3h8 + 5o2 > 3co2 + 4h2o

5: 1
10: 11
10: 3
1: 10

lithium reacts with bromine (br2) in a synthesis reaction to produce lithium bromide. determine the limiting reactant if 25.0 grams of lithium and 25.0 grams of bromine are present at the beginning of the reaction.

limiting reactant = bromine
limiting reactant = lithium
limiting reactant = both lithium and bromine
neither lithium nor bromine are the limiting reactant because they are both equal