Answer:
The atomic mass of nitrogen is
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14.0067 u</h2>
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<em>You learn more from failure than from success</em></h2>
Answers:
Density = 0.8 g/mol.
Given data:
v = 25 ml
m = 20 g
δ = ?
Solution:
Formula for calculating density is given as,
Density = Mass / Volume
putting values
Density = 20.0 g / 25 ml
Density = 0.8 g/mol.
Answer:
Option d. 0.10 m Cr₂(SO₄)₃
Explanation:
Formula for the osmotic pressure is determined as:
π = M . R . T . i
So you have to take account the i (Van't Hoff factor, numbers of ions dissolved)
Urea is an organic compound, so the i value is 1
Zync acetate can be dissociated:
Zn(CH₃COO)₂ → 1Zn²⁺ + 2CH₃COO⁻
In this case, the i is 3. (you see, the stoichiometry of ions)
Cr₂(SO₄)₃ → 0.10 m
Chromium sulfate is dissociated:
Cr₂(SO₄)₃ → 2Cr³⁺ + 3SO₄⁻²
i = 5
BaI₂ → 0.16 m
BaI₂ → 1Ba²⁺ + 2I⁻
i = 3
A) iron melting is the only example of physical change, because it's just a change of state (from solid to liquid).
The others, rusting, combustion, and decay are all chemical changes, because it will result in changing the chemical bonds between the atoms.
B- Carbon nitrogen and oxygen. All organisms are made up of carbon, oxygen is essential to breath, and nitrogen makes up most of earth's atmosphere.
