The answer iiiis... A: Group 8A, Period 1
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Here's why:</h3>
The way I found this doesn't have much thought or explanation--I just remember that helium and hydrogen are in period 1. The only answer choice with "period 1" is A.
Answer:
9,000, 100 has 7 significant figures
Explanation:
Answer:
80 liters
Explanation:
At STP, 1 mole of ideal gas has a volume of 22.4 liters.
Therefore, since liters and moles are directly proportional, we can use stoichiometry directly.
40L CH₄ × (2L H₂ / 1L CH₄) = 80L H₂
Hey!
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Steps To Solve:
~Substitute
3(2) - 2(3)
~Subtract
6 - 6
~Simplify
0
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Answer:
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Hope This Helped! Good Luck!
Answer:
We need 7.5 mL of the 1M stock of NaCl
Explanation:
Data given:
Stock = 1M this means 1 mol/ L
A 0.15 M solution of 50 mL has 0.0075 moles NaCl per 50 mL
Step 2: Calculate the volume of stock we need
The moles of solute will be constant
and n = M*V
M1*V1 = M2*V2
⇒ with M1 = the initial molair concentration = 1M
⇒ with V1 = the volume we need of the stock
⇒ with V2 = the volume we want to make of the new solution = 50 mL = 0.05 L
⇒ with M2 = the concentration of the new solution = 0.15 M
1*V1 = 0.15*(50)
V1 = 7.5 mL
Since 0.0075 L of 1M solution contains 0.0075 moles
50 mL solution will contain also 0.0075 moles but will have a molair concentration of 0.0075 moles / 0.05 L =0.15 M
We need 7.5 mL of the 1M stock of NaCl
