Given:
n = 0.0021 mol
M = 44 gram/mol
Required: m or the mass of the molecule
Solution:
M = m/n
Rearranging the expression,
m = M x n
m = 44 g/mol x 0.0021 mol
Evaluating the expression and cancelling units, we obtain,
m = 0.0924 grams
M is the molar mass. This value is very useful in chemistry calculations especially in calculating the amounts of reactants and products for a chemical reaction.
The answer is: " 56 g CaCl₂ " .
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Explanation:
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2.0 M CaCl₂ = 2.0 mol CaCl₂ / L ;
Since: "M" = "Molarity" (measurement of concentration);
= moles of solute per L {"Liter"} of solution.
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Note the exact conversion: 1000 mL = 1 L .
Given: 250 mL ;
250 mL = ? L ? ;
250 mL * (1 L / 1000 L) = (250/1000) L = 0.25 L .
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(2.0 mol CaCl₂ / L ) * (0.25L) = (2.0) * (0.25) mol = 0.50 mol CaCl₂ ;
We have: 0.50 mol CaCl₂ ; Convert to "g" (grams):
→ 0.50 mol CaCl₂ .
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1 mol CaCl₂ = ? g ?
From the Periodic Table of Elements:
1 mol Ca = 40.08 g
1 mol Cl = <span>35.45 g .
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There are 2 atoms of Cl in " CaCl₂ " ;
→ Note the subscript, "2", in the " Cl₂ " ;
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So, to calculate the molar mass of "CaCl₂" :
40.08 g + 2(35.45 g) =
40.08 g + 70.90 g = 110.98 g ; round to 4 significant figures;
→ round to 111 g/mol .
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So:
→ 0.50 mol CaCl₂ = ? g CaCl₂ ? ;
→ 0.50 mol CaCl₂ * (111 g CaCl₂ / mol CaCl₂) ;
= (0.50) * (111 g) CaCl₂ ;
= 55.5 g CaCl₂ ;
→ round to 2 significant figures;
→ 56 g CaCl₂ .
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The answer is: " 56 g CaCl₂ " .
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Option A is correct. When a person says "<em>I think</em><em> that between an elephant and a monkey that jumped off the cliff, both of them will hit the ground at the same time."</em> the person is stating his Hypothesis
A hypothesis is an explanation proposed or given based on a piece of evidence that is limited.
It is useful at the beginning of an investigation because it serves as the building block for an impending fact or law.
From the statement, we can see that the person is not too sure of the information provided since he "thinks". <em>He said, </em><em>"I think</em><em> that between an elephant and a monkey that jumped off the cliff, both of them will hit the ground at the same time." </em>
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Hence we can conclude that the person is stating a hypothesis.
Law and theory are incorrect because they are already proven facts.
Learn more here: brainly.com/question/6907236
It is a physical change when cream mixes with
coffee, it changes the color of the coffee. When you add more or less cream there
is a color change depending on the consistency of cream. The
properties are not changes and a no new compound is formed as in chemical
change with a reaction of two compounds, a new compound is formed with
different properties. So it is a physical change.
