4 moles of hydrogen = 4 * 1.008 = 4.032 grams
1 mole of helium = 4.003 grams
Difference is 4.032 - 4.003
= 0.029 g
Answer:
150.0 mL.
Explanation:
- It is known that the no. of millimoles of HNO₃ before dilution = the no. of millimoles of HNO₃ after dilution.
∵ (MV) before dilution = (MV) after dilution.
<em>∴ V before dilution = (MV) after dilution / M before dilution</em> = (0.15 M)(500.0 mL)/(0.50 M) = <em>150.0 mL.</em>