The relation between density, mass and volume is
1) to calculate = volume
given:
Density = 0.0915 g/ mL
mass = 17.7 grams
formula used:
Thus
Volume 
Answer: 193.44 mL
2) the mass of sample will be
Answer: 7 g
H^+ = acid
OH^- = alkaline
Acids have a pH of below 7. The lower the number, the strongest the acid.
Answer:
a) KOH
Explanation:
In the given balanced reaction
2K + 2H2O → 2KOH + H2
In the compound KOH,
The elements are K,O, and H and in the compound, there is one mole each of K , O ,and H.
So the element ratio here is 1 : 1 : 1.
The density of He is 1.79 x 10⁻⁴ g/mL
In other words in 1 mL there's 1.79 x 10⁻⁴ g of He.
To fill a volume of 6.3 L the mass of He required
= 1.79 x 10⁻⁴ g/mL * 6300 mL
= 11 277 * 10⁻⁴ g
Therefore mass of He required = 1.1277 g of He
