Answer : The formula of the gas produced is,
(phosphine gas)
Explanation :
According to the question, when sodium phosphide is treated with water then it react to give phosphine gas and sodium hydroxide.
The balanced chemical reaction will be:

By Stoichiometry of the reaction we can say that:
1 mole of sodium phosphide reacts with 3 moles of water to give 1 mole of phosphine gas and 3 moles of sodium hydroxide.
Thus, the formula of the gas produced is,
(phosphine gas)
true gas molicules bounce off one another much faster liquid just slides
Answer:
Proxima Centuri is 9 orders of magnitude further from New York compared to Perth
Explanation:
Distance of Proxima Centuri to New York = 4 × 10^16 meters
Distance of Proxima Centuri to Perth = 11000 miles
Since 1 mile = 1609 meters, distance to Perth in meters = 11000 × 1609
Distance to Perth = 17699000 = 1.7699 × 10^7 meters
Order of magnitude of the distances of Proxima Centuri to New York and Perth = 10^16/10^7
Order of magnitude = 10^9
Therefore, Proxima Centuri is 9 orders of magnitude further from New York compared to Perth.
V ( HCl ) = 16.4 mL / 1000 => 0.0164 L
M( HCl) = ?
V( KOH) = 12.7 mL / 1000 => 0.0127 L
M(KOH) = 0.620 M
Number of moles KOH:
n = M x V
n = 0.620 x 0.0127
n = 0.007874 moles of KOH
number of moles HCl :
<span>HCl + KOH = H2O + KCl
</span>
1 mole HCl ------ 1 mole KOH
<span>? mole HCl--------0.007874 moles KOH
</span>
moles HCl = 0.007874 * 1 / 1
= 0.007874 moles of HCl
M = n / V
M = 0.007874 / <span>0.0164
</span>= 0.480 M
Answer (2)
hope this helps!