This is probably wrong but i think the answer is 1,979,381.44
Answer:
Explanation:
Identify all of the compounds present:
- aqueous copper(II) sulfate: we have copper charged as 2+, sulfate anion has a charge of 2-. This means the charges are balanced if we take 1 ion of each to give ;
- solid iron metal: iron metal is Fe, then including the state of iron, we have ;
- aqueous iron(II) sulfate: iron has a charge of 2+, sulfate has a charge of 2-, so the positive charge balances the negative charge to give a formula of ;
- solid copper metal: copper metal is Cu, then including the state of copper, we have .
We then have a reaction:
Half-life is the time required for decay of 50% of radio-active nuclei.
Thus, when radio-active material crosses 1st half-life, 100/2 = 50% radio-active material is left and remaining 50% is elapsed.
When, when radio-active material crosses 2nd half-life, 50/2 = 25% radio-active material is left and remaining 75% is elapsed.
When radio-active material crosses 3rd half-life, 25/2 = 12.5% radio-active material is left and remaining 87.5% is elapsed.
Thus, 2 <span>half-lives must elapse until 84 % of a radioactive sample of atoms has decayed.</span>
Based on the ideal gas relation:
PV = nRT
where P = pressure ; V = volume ; T = temperature
n = number of moles; R = gas constant = 0.0821 L atm/mol-K
Step 1: Find the number of moles of O2
n = PV/RT = 1 * 3.90/0.0821*273 = 0.1740 moles
Step 2: Calculate the molecules of O2
Now, 1 mole of O2 corresponds to 6.023 * 10²³ molecules of O2
Therefore, 0.1740 moles of O2 corresponds to-
0.1740 moles of O2 * 6.023*10²³ molecules of O2/1 mole of O2
= 1.048 * 10²³ molecules of O2