Answer:
Molarity = 3.625 M
Explanation:
Given data:
Mass of HCl = 53.0 g
Volume of water = 400.0 mL (400/1000 = 0.4 L)
Molarity of solution = ?
Solution:
Number of moles of of HCl:
Number of moles = mass/ molar mass
Number of moles = 53 g/ 36.5 g/mol
Number of moles =1.45 mol
Molarity:
Molarity = number of moles of solute / volume of solution in L
Molarity = 1.45 mol / 0.4L
Molarity = 3.625 M
Greetings!
To find the empirical formula you need the relative atomic mass of each element!
Li = 6.9
C = 12
O = 16
You can simply change the percentages into full grams
Li = 18.8g
C = 16.3g
O = 64.9
Then you use this to find the Number of moles = amount in grams / atomic mass
Li = 18.8 ÷ 6.9 = 2.7246
C = 16.3 ÷ 12 = 1.3583
O = 64.9 ÷ 16 = 4.0562
Then divide each number of moles by the smallest value:
Li = 2.7246 ÷ 1.3583 = 2.0
C = 1.3583 ÷ 1.3583 = 1
O = 4.0562 ÷ 1.3583 = 2.9 ≈ 3
So that means that there are 2 Li, 1 C, and 3 O
Empirical formula would be:
Li₂CO₃
Hope this helps!
Answer:
Precision refers to how close two or more measurements are to each other, regardless whether those measurements are accurate or not.
Accuracy refers to how closely the measured value of a quantity corresponds to its “true” value.
Explanation:
Answer:
Half life is the time taken by a radio active isotope to reduce by half of its original amount. Radium-226 has a half life of 1602 years meaning that it would take 1602 years for a mass of radium to reduce by half.
Number of half lives in 9612 years = 9612/1602 = 6 half lives
New mass = Original mass x (1/2)n where n is the number of half lives.
Therefore, New mass= 500 x (1/2)∧6
= 500 x 0.015625
= 7.8125 g
Hence the mass of radium after 9612 years will be 7.8125 grams.
Explanation:
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