Answer:
See explanation
Explanation:
Molar mass of NaCl = 58.5 g
Number of moles contained in 10 g of NaCl = 10 g/58.5 g = 0.17 moles
If 1 mole of NaCl contains 6.02 * 10^23 atoms
0.17 moles of NaCl contains 0.17 * 6.02 * 10^23 atoms = 1.02 * 10^23 atoms
Molar mass of Fe II chloride = 126.751 g/mol
Number of moles = 10 g/126.751 g/mol = 0.0789 moles
Number of atoms = 0.0789 moles * 6.02 * 10^23 atoms = 4.7 * 10^22 atoms
Molar mass of Na = 23 g/mol
Number of moles = 10g/23 g/mol = 0.43 moles
Number of atoms = 0.43 moles * 6.02 * 10^23 atoms = 2.59 * 10^ 23 atoms
Answer:
1. B
2. C
Explanation: The law that the properties of the elements are periodic functions of their atomic numbers. And the second one is, most of the air we breathe is made of oxygen.
Answer:
Variation within genes leads to different genotypes , which can be seen by the individuals having different phenotypes . For example, the dogs above all have different fur colours and fur lengths. Genetic and environmental variation combine together to produce these different phenotypes.
First, we need to get the value of Ka:
when Ka = Kw / Kb
we have Kb = 1.8 x 10^-5
and Kw = 3.99 x 10^-16 so, by substitution:
Ka = (3.99 x 10^-16) / (1.8 x 10^-5) = 2.2 x 10^-11
by using the ICE table :
NH4+ + H2O →NH3 + H+
intial 0.013 0 0
change -X +X +X
Equ (0.013-X) X X
when Ka = [NH3][H+] / [NH4+]
by substitution:
2.2 x 10^-11 = X^2 / (0.013 - X) by solving this equation for X
∴X = 5.35 x 10^-7
∴[H+] = X = 5.35 x 10^-7
∴PH = - ㏒[H+]
= -㏒(5.35 x 10^-7)
= 6.27
Answer:
The independent variable in this experiment is what he feeds the chickens (rice or corn).
Explanation:
The independent variable is the variable the experimenter manipulates or changes.
