Answer:
<h2>2.54 moles</h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula

where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have

We have the final answer as
<h3>2.54 moles</h3>
Hope this helps you
Ionic compounds share electrons :)
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
Answer:- D. 1.8 moles of Fe and
.
Solution:- The balanced equation is:

let's first figure out the limiting reactant using the given moles and mol ratio:

= 5.4 mol CO
From calculations, 5.4 moles of CO are required to react completely with 1.8 moles of Iron(III)oxide but only 2.7 moles of CO are available. It means CO is limiting reactant.
Products moles depends on limiting reactant. Let's calculate the moles of each reactant formed for given 2.7 moles of CO.

= 1.8 mol Fe

= 
So, the correct choice is D. 1.8 moles of Fe and
are formed.
To determine the temperature of the gas, we need to assume ideal gas to use the equation PV=nRT where P represents the pressure, V is the volume, n is the number of moles, T is the temperature and R is the universal gas constant. We calculate as follows:
PV = nRT
T = PV / nR
T = (1.26 atm) ( 208 L ) / 0.08205 L-atm/mol-K ( 9.95 mol )
T = 321.02 K
Hope this answers the question.