Answer:
Mass of Rb-87 is 86.913 amu.
Explanation:
Given data:
Average mass of rubidium = 85.4678 amu
Mass of Rb-85 = 84.9117
Ratio of 85Rb/87Rb in natural rubidium = 2.591
Mass of Rb = ?
Solution:
The ration of both isotope is 2.591 to 1. Which means that for 2.591 atoms of Rb-85 there is one Rb-87.
For 100% naturally occurring Rb = 2.591 + 1 = 3.591
% abundance of Rb-85 = 2.591/ 3.591 = 0.722
% abundance of Rb-87 = 1 - 0.722= 0.278
84.9117 × 0.722 + X × 0.278 = 85.4678
61.306 + X × 0.278 = 85.4678
X × 0.278 = 85.4678 - 61.306
X × 0.278 = 24.1618
X = 24.1618 / 0.278
X = 86.913 amu
The interaction between the substances and stomata is a chemical reaction, light energy strikes at the chlorophyll molecules, whose electrons gets excited to a state of higher energy, and they come back to their state of lower energy by emission of energy, which is accepted by a chain of acceptors, and energy is generated.
0.448 moles of ions will form when a 42.66-gram sample of magnesium chloride is dissolved in water (option A).
<h3>How to calculate number of moles?</h3>
According to this question, when magnesium chloride (MgCl2) dissolves in water, it dissociates into magnesium ions and chloride ions as follows:
MgCl2(aq) ⟶ Mg2+(aq) + Cl−(aq)
However, if a 42.66-gram sample of magnesium chloride is dissolved in water, this means that 42.66g/molecular mass of MgCl2 will be the number of moles of the ionic products.
molecular mass of MgCl2 = 95.3g/mol
moles = 42.66g ÷ 95.3g/mol = 0.448mol
Therefore, 0.448 moles of ions will form when a 42.66-gram sample of magnesium chloride is dissolved in water.
Learn more about moles at: brainly.com/question/26416088
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A Bronsted-Lowry acid-base is a molecule or ion that donates a hydrogen ion in a reaction.
<em>Brainliest Please?</em>
I guess examples of solid and gas???? You have to be more descriptive.....
