Answer:
M = 0.138 M
Explanation:
Given data:
Mass of glucose = 12.55 g
Volume of solution = 500 mL
Molarity of solution = ?
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Number of moles of glucose:
Number of moles = mass/molar mass
Number of moles = 12.55 g/ 180.156 g/mol
Number of moles = 0.069 mol
Volume in L:
500 mL × 1 L /1000 mL
0.5 L
Molarity:
M = 0.069 mol / 0.5 L
M = 0.138 M
Answer:
Explanation:
Given that,
Mass of sample, m = 996.9 g
The change in temperature of the sample, 
Heat produced, Q = 62.9 calories = 263173.6 J
The heat released by a sample due to change in temperature is given by :
Where
c is the specific heat capacity
So,
So, the specific heat of ethanol is equal to 
.
Answer:
Energy lost is 7.63×10⁻²⁰J
Explanation:
Hello,
I think what the question is requesting is to calculate the energy difference when an excited electron drops from N = 15 to N = 5
E = hc/λ(1/n₂² - 1/n₁²)
n₁ = 15
n₂ = 5
hc/λ = 2.18×10⁻¹⁸J (according to the data)
E = 2.18×10⁻¹⁸ (1/n₂² - 1/n₁²)
E = 2.18×10⁻¹⁸ (1/15² - 1/5²)
E = 2.18×10⁻¹⁸ ×(-0.035)
E = -7.63×10⁻²⁰J
The energy lost is 7.63×10⁻²⁰J
Note : energy is lost / given off when the excited electron jumps from a higher energy level to a lower energy level
Answer:
<h2>
</h2>
Explanation:
<u>First of all cross multiply</u>
That's
<u>Next divide both sides by </u>
<u> in order to isolate </u>
We have
We have the final answer as
Hope this helps you
Answer:
22.22 g
Explanation:
The balanced reaction equation is;
Ca(s) + 2HCl(aq) → CaCl2(aq) + H2(g)
Number of moles of calcium reacted = 8.02g/40.1g/mol = 0.2 moles of Calcium
From the reaction equation;
1 mole of Ca yields 1 mole of CaCl2
Hence 0.2 moles of Ca also yields 0.2 moles of CaCl2
Mass of calcium chloride produced = number of moles * molar mass
Mass of calcium chloride = 0.2 moles of CaCl2 * 111.1g/mol = 22.22 g
