<span>2H2 + O2 → 2H2O</span>
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<span>okay???</span>
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Answer : The final pressure of the gas will be, 26.8 kPa
Explanation :
According to the Boyle's law, the pressure of the gas is inversely proportional to the volume of the gas at constant temperature of the gas and the number of moles of gas.

or,

or,

where,
= initial pressure of the gas = 209 kPa
= final pressure of the gas = ?
= initial volume of the gas = 10.0 L
= final volume of the gas = 78.0 L
Now put all the given values in this formula, we get the final pressure of the gas.


Therefore, the final pressure of the gas will be, 26.8 kPa
Electron because it’s more valid than neutron
The answer is B, early in the morning water covered areas (lakes,ponds,puddles,etc.) will vaporize a little bit because of the heat from the sun and it will continue all day, vapors rise towards the atmosphere and since it's a lot cooler there it will condense into a cloud which is full of tiny frozen water particles. Hope this helps <span />
Molar mass :
NaBr = 103 g/mol
Pb(NO3)2 = 331.20 g/mol
<span><span /><span>Balanced chemical equation :
</span></span>2 NaBr + 1 Pb(NO3)2 = 2 NaNO3 + 1 PbBr<span>2
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2*103 g NaBr ------------> 1 * 331.20 g Pb(NO3)2
g NaBr -------------------> 311 g Pb(NO3)2
331.20 g = 2*103*311
331.20 g = 64066
mass ( NaBr ) = 64066 / 331.20
mass ( naBr) = 193,43 g of NaBr
hope this helps!.
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