Chemistry help ! ! !?
One mole of calcium ions has the same number of representative particles as which of the following?
one mole of calcium nuclei
one mole of calcium atoms
6.02 x 1023 calcium ions
all of the above
How did Amedeo Avogadro contribute to the development of the mole concept?
He proposed that under identical conditions, equal volumes of all gases contain the same number of particles.
He calculated the mass of one mole of carbon-12 atoms.
He hypothesized that samples of equal mass contain the same number of diatomic molecules.
He proved that volumes of reactant and product gases are related by small, whole-number ratios.
The mole is most similar to:
a pound (a measure of weight)
a liter (a measure of volume)
a dozen (a measure of number)
a gram (a measure of mass)
If you are given the number of molecules in an unidentified chemical compound, can you calculate the number of moles in this sample?
yes, because you know that each mole contains 6.02 x 1023 molecules
yes, as long as you can also measure the mass of the sample
no, because the number of moles depends on the volume of the sample
no, because the number of moles depends on the identity of the substance
There are 1.204 x 1024 molecules of H2 in a sample. How many moles does this represent?
What is the molar mass of Fe2Br3?
1.35 x 102 g/mole
3.27 x 102 g/mole
3.51 x 102 g/mole
8.14 x 102 g/mole
What does the molar mass of an element represent?
the value of the element's atomic weight in units of grams per mole
the mass of 1 mole of the element
the mass of 1000 atoms of the element
both choices a and b
What is the molar mass of Mg(ClO2)2 ?
How many potassium atoms are in 250.0 grams of potassium?
1.66 x 10−24 atoms K
3.85 x 1024 atoms K
1.51 x 1026 atoms K
5.88 x 1027 atoms K
How many grams are in 23.0 moles of carbon?
2.76 x 102 grams
1.67 x 1026 grams
8.87 x 10−22 grams