Answer:
Number of molecules = 23.9 × 10²³ molecules
Number of moles = 3.97 mol
Explanation:
Mass of HNO₃ = 250 g
Number of moles = ?
Number of molecules = ?
Solution:
Number of moles = mass / molar mass
Number of moles = 250 g/63 g/mol
Number of moles = 3.97 mol
Number of molecules:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For 250 g of HNO₃:
250 g/ 63 g/mol = 3.97 mole
3.97 × 6.022 × 10²³ molecules = 23.9 × 10²³ molecules
Answer:
25.0g is the mass of sulfur
Explanation:
The sulfur and the oxygen are 50:50. That means there is 1 mole of S per mole of O.
To solve this question we need to convert the mass of O to moles, as moles of O = Moles of S, we can find the moles of S and its mass:
<em>Moles O = Moles S:</em>
12.5g O * (1mol / 16g) = 0.781 moles
<em>Mass S:</em>
0.781 moles * (32g / mol) =
<h3>25.0g is the mass of sulfur</h3>
The answer would be
35 ============= > A CL = ============> CL 17 === = ======== >Z
37 CL 17 Isotopes mean A different and equal Z.
Isotopes are atoms that have the same number of protons but a different number of neutrons but still belong to the same element. Though they have the same atomic number but not the same mass number.
Answer:
Bohrium (Niels Bohr)
Curium (Marie and Pierre Curie)
Einsteinium (Albert Einstein
