The mass of 165.0 g sample that remains after 90.0 minutes is 5.16 grams
calculation
lambda㏑2/18= 0.0385
m(t)= 165 x e( 0.0385 x90) =5.16g
Answer:
The Law of Definite Proportions ensures that chemical compounds are always created using the same proportions, regardless of the amount of the compound which is being made
Answer:
I think the answer is A.
please give thanks if it helps
and sorry if it doesn't help.
1) How old is a bone in which the Carbon-14 in it has undergone 8 half-lives?
Using the graph form the picture you count 8 times the halving of C¹⁴ and you arrive at 45600 years.
2) In the process of radiocarbon dating, the fixed period of radioactive decay used to determine age is called the half-life.
3) A certain byproduct in nuclear reactors, 210Po, decays to become 206Pb. After a time period of about 276 days, only about 25% of an original sample of 210Po remains. The remainder has decayed to 206Pb. Determine the approximate half-life of 210Po.
What the problem is telling you is that at 276 days only 25% original sample remains. If you divide the number of days by two the quantity of original sample will be multiplied by two, and you will have 138 days and 50% of original sample. This is the answer because the the half-life of a isotope is the time in which 50% of original quantity of radioactive atoms will disintegrate.
Answer: 20) 2365 g
21) 22.39 grams.
22) 29.99 g
Explanation: 20) molarity is the no of moles of solute per unit volume.
We can calculate amount of CaCl2 required to prepare 0.1 M CaCl2 1000 ml solution.
we know that to prepare one ltr of 1 M solution of CaCl2 111 g required
Now consider x gram will require to prepare to
so that comparing above both condition
1000ml ×1M×X g=1000ml×0.1M×111g
X= 11.1 gram
X= 11.1 g of CaCl2
Hence 11.1 g of CaCl2 would be dissolved in 1.0L of a 0.100 M solution of CaCl2
21) How many moles of CaCl₂ in that solution?
;
;
.
What's the mass of that 0.20172 moles of CaCl₂?
Molar mass from a modern periodic table:
Ca- 40.078;
Cl- 35.45.
Molar mass of CaCl₂:
.
Mass of that 0.20172 moles of CaCl₂:
22) its a 3.0m solution so 1 litre of solution contains 3 moles of NaOH, 250ml of solution contains 0.25x39.9971 g/mol, so 250ml of this solution contains 0.75x39.9971=29.99g, or if you round it up 30.0g
