Answer:
<h3>The answer is 0.23 moles</h3>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>0.23 moles</h3>Hope this helps you
Answer:- Heat lost by the metal is 279.45 cal.
Solution:- This type of problems are solved by using the concept, heat given = - heat taken
Metal temperature is decreasing from 45.00 degree C to 11.08 degree C. It means the heat is lost by the metal and this heat lost by metal is gained by water and the calorimeter to raise their temperature.
the equation we use is, .
where, q is the heat energy, m is mass, c is specific heat and is change in temperature.
Combined mass of calorimeter and water is 250.0 g and the specific heat is .
for calorimeter and water (combined) = 11.08 - 10.00 = 1.08 degree C
for metal = 11.08 - 45.00 = -33.92 degree C
let's plug in the values in the above equation and calculate heat gained by combined system.
q=250.0g*\frac{1.035cal}{g.^0C}*1.08^0C
q = 279.45 cal
So, the heat lost by the metal is 279.45 cal.