Answer:
Nitrogen, Hydrogen, Oxygen, Chlorine, and Fluorine are all gases at room temperature.
Explanation:
Missing question: 0,535 gram of KIO₃ dissolved in 250 mL of de-ionized water to <span>make primary standard solution.
m(</span>KIO₃) = 0,535 g.
V(KIO₃) = 250 mL ÷ 1000 mL/L = 0,25 L.
n(KIO₃) = m(KIO₃) ÷ M(KIO₃).
n(KIO₃) = 0,535 g ÷ 214 g/mol.
n(KIO₃) = 0,0025 mol.
c(KIO₃) = n(KIO₃) ÷ V(KIO₃).
c(KIO₃) = 0,0025 mol ÷ 0,25 L.
c(KIO₃) = 0,01 mol/L = 0,01 M.
Answer:
1.5 x 10²²atoms
Explanation:
Given parameters:
Mass of Br = 1.98g
Unknown:
Number of atoms
Solution:
A mole of a substance is the amount of substance contained in the avogadro's number of particles.
To solve this problem, we must first find the number of moles present in the given mass of the Br atom:
Number of moles =
=
= 0.025mole.
Now we know that:
1 mole = 6.02 x 10²³
0.025 mole = 0.025 x 6.02 x 10²³ = 1.5 x 10²²atoms