Answer:
They are salts, ionic compounds
Explanation:
To know if they are covalent or ionic we need to check their difference in electronegativity. As an example mgcl2, mg has electronegativity of 1.2 and cl 3 so 3-1.2=1.8 which is bigger than 1.7 means it's ionic therefore they are salts
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Both America and Kenya have a high level of possible crop damage by insects. America is able to afford insecticides and the research to go with it, to control the pests. In Kenya farmers rotate their crops as much as possible (not always possible) and this helps in reducing the risk of pests. Also Kenyan farmers often grow rice in adjacent fields with sweet potatoes; this has reduced the weevil infestation level in sweet potatoes. The same technique can be used using sweet potato, intercropped with millet and sesame.
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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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0.1 km
2cm/year * 5000 yrs = 10000 cm
1cm= .01 m
1km = 1000 m
so the answer is 0.1 km
