Answer:
The answer to your question is 25 grams
Explanation:
Data
half-life = 5730 years
sample = 200 g
after 3 half-lives
Process
Calculate the amount of sample after one, two and three half-lives.
After each half-life, that of sample is half the previous amount.
Number of half-lives Amount of sample
0 200 g
1 100 g
2 50 g
3 25 g
Answer: The answer to the first one is the second option and the answer for the second one is the first option.
Explanation:
<h3>
Answer:</h3>
1.85 M
<h3>
Explanation:</h3>
<u>We are given;</u>
- Number of moles as 0.50 mol
- Volume of the solution is 270 ml
But, 1000 mL = 1 L
- Thus, volume of the solution is 0.27 L
We are required to calculate the molarity of the solution;
- Molarity refers to the concentration of a solution in moles per liter.
- It is calculated by dividing number of moles with the volume.
Molarity = Moles ÷ Volume
In this case;
Molarity = 0.50 moles ÷ 0.27 L
= 1.85 Mol/L or 1.85 M
Therefore, molarity of the solution is 1.85 M
Answer:
Weigh the empty crucible, and then weigh into it between 2 g and 3 g of hydrated copper(II) sulphate. Record all weighings accurate to the nearest 0.01 g.
Support the crucible securely in the pipe-clay triangle on the tripod over the Bunsen burner.
Heat the crucible and contents, gently at first, over a medium Bunsen flame, so that the water of crystallisation is driven off steadily. The blue colour of the hydrated compound should gradually fade to the greyish-white of anhydrous copper(II) sulfate. Avoid over-heating, which may cause further decomposition, and stop heating immediately if the colour starts to blacken. If over-heated, toxic or corrosive fumes may be evolved. A total heating time of about 10 minutes should be enough.
Allow the crucible and contents to cool. The tongs may be used to move the hot crucible from the hot pipe-clay triangle onto the heat resistant mat where it should cool more rapidly.
Re-weigh the crucible and contents once cold.
Calculation:
Calculate the molar masses of H2O and CuSO4 (Relative atomic masses: H=1, O=16, S=32, Cu=64)
Calculate the mass of water driven off, and the mass of anhydrous copper(II) sulfate formed in your experiment
Calculate the number of moles of anhydrous copper(II) sulfate formed
Calculate the number of moles of water driven off
Calculate how many moles of water would have been driven off if 1 mole of anhydrous copper(II) sulfate had been formed
Write down the formula for hydrated copper(II) sulfate.
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Explanation:
Https://www.google.com/search?q=how+to+solve+fir+atomic+mass+in+chemisty&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari#kpvalbx=1
Here is the link to a great video that explains your question nicely, hope this helps.
