Answer: There is no list in your question. But the three factors in which natural selection occurs are:
1. A struggle for existence,
2. Variation and
3. Inheritance
Explanation:
Darwin’s theory of natural selection is the way in which organisms change overtime.
These changes allow organisms to become better adapted to their environment and increase their chances for survival.
The three major factors through which natural selection occurs are:
1. A struggle for existence,
2. Variation and
3. Inheritance
Darwin’s theory of natural selection will occur if the three conditions above are met and unless these factors are in place, natural selection will not occur.
Answer:
CH₂ ; 67.1 %
Explanation:
To determine the empirical formula we need to find what the mole ratio is in whole numbers of the atoms in the compound. To do that we will first need the atomic weights of C and H and then perform our calculation
Assume 100 grams of the compound.
# mol C = 85.7 g / 12.01 g/mol = 7.14 mol
# mol H = 14.3 g / 1.008 g/mol = 14.19 mol
The proportion is 14.9 mol H/ 7.14 mol C = 2 mol H/ 1 mol C
So the empirical formula is CH₂
For the second part we will need to first calculate the theoretical yield for the 12.03 g NaBH₄ reacted and then calculate the percent yield given the 0.295 g B₂H₆ produced.
We need to calculate the moles of NaBH₄ ( M.W = 37.83 g/mol )
1.203 g NaBH₄ / 37.83 g/mol = 0.0318 mol
Theoretical yield from balanced chemical equation:
0.0318 mol NaBH₄ x 1 mol B₂H₆ / mol NaBH₄ = 0.0159 mol B₂H₆
Theoretical mass yield B₂H₆ = 0.0159 mol x 27.66 g/ mol = 0.440 g
% yield = 0.295 g/ 0.440 g x 100 = 67.1 %
Answer:
The answer to your question is: letter A
Explanation:
A combination reaction is when there are two reactants that gives only one product.
a. 2SO2 + O2—> 2SO3 This is a combination reaction,
2 reactants gives one product.
b. Zn + Cu(NO3)2–>Zn(NO3)2 + Cu This is not a combination reaction,
it's a single replacement reaction.
c. 2H2O2–> 2H2O+O2 This is a decomposition reaction
d. AgNO3 + NaCl → AgCl+NaNO3 THis is a double replacement reaction.
Answer:
Mass = 153.48 g
Explanation:
Given data:
Volume of solution = 2.50 L
Molarity = 0.48 M
Mass required = ?
Solution:
Molarity = number of moles / volume in litter
Number of moles = Molarity × volume in litter
Number of moles = 0.48 M × 2.50 L
Number of moles = 1.2 mol
Mass of HI:
Number of moles = mass/molar mass
Mass = Number of moles × molar mass
Mass = 1.2 mol × 127.9 g/mol
Mass = 153.48 g
-3 - 3(-2) = +3
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