Answer:
21. Erosion causes physical changes. For example - Land degradation, deforestation.
20. B statement is closely related to climate.
hope it helps!
Answer:
four 0.5 times 10 to the 23rd Adams of Neptune
Explanation:
Answer:
A = Molarity = 0.22 M
B = Molarity = 0.36 M
Explanation:
Given data:
For first solution:
number of moles = 0.550 mol
Volume of solution = 2.50 L
Molarity = ?
Molarity:
Formula:
Molarity = number of moles of solute / volume of solution in L.
Molarity = 0.550 mol / 2.50 L
Molarity = 0.22 M
For second solution:
Mass of NaCl = 15.7 g
Volume of solution = 709 mL or 709/1000 = 0.709 L
Molarity = ?
Solution:
Number of moles = mass / molar mass
Number of moles = 14.7 g/ 58.44 g/mol
Number of moles = 0.252 mol
Molarity:
Molarity = number of moles of solute / volume of solution in L.
Molarity = 0.252 mol / 0.709 L
Molarity = 0.36 M
Osmolarity=osmole of the solute/litres of the solution
ionic equation for dissociation of CaCl2 is
CaCl2--->Ca2+ +2Cl-
total osmoles for reaction are 1(Ca2+) + 2(Cl-)= 3 osmoles
therefore
0.50 moles of CaCl2 x 3 osmoles/ 1mole of CaCl2 = 1.5osmoles
osmolarity=1.5 /1.0 L=1.5 osmol/l
