Answer : The mass of
required is 18.238 grams.
Explanation : Given,
Mass of
= 83.10 g
Molar mass of
= 146 g/mole
Molar mass of
= 256.52 g/mole
The balanced chemical reaction is,

First we have to determine the moles of
.

Now we have to determine the moles of
.
From the balanced chemical reaction we conclude that,
As, 8 moles of
produced from 1 mole of 
So, 0.569 moles of
produced from
mole of 
Now we have to determine the mass of
.


Therefore, the mass of
required is 18.238 grams.
B3+ is isoelectronic with helium.
Isoelectronicity is the phenomenon whereby two or more molecular entities have the same number of electrons or similar electronic configuration regardless of the nature of the elements that are involved.
In the question given above, helium and B3+ have the same number of electrons. Helium has two electrons. Boron has five electrons but it has given away three of the electrons [that is why it has a charge of +3] and it now has only two left.
Answer:
The final temperature of the system is 27.3°C.
Explanation:
Heat lost by aluminum = 3.99 × 0.91 × (100-T)
= 3.631 (100-T)
Heat gained by water = 10 × 4.184 × (T-21)
= 41.84 (T-21)
As,
Heat gained = Heat loss
or, 3.631(100-T) = 41.84(T-21)
or,363.1 - 3.631 T = 41.84 T - 878.64)
or, (41.84+ 3.631) T = 878.64 +363.1
or T= 
or, T = 27.3°C
Hence the final temperature is 27.3°C.
Answer:
An Arrhenius Base
Explanation:
The definition of this is a base that is a hydroxide ion donor.
of oxygen at STP would be required to react completely with 38.8g of propane.
<u>Given that :</u>
molar mass of propane = 44 g/mol
mass of propane = 38.8 g
∴ Moles present in 38.8 g of propane =
= 0.88 mole
<u>applying rule of balanced equations </u>
1 mole of propane = 5 moles of oxygen
0.88 mole of propane = 5 * 0.88 = 4.4 moles of oxygen
Note : volume of 1 mole of oxygen at STP = 
∴Total volume of oxygen required at STP = 22.4 * 4.4 = 
Hence we can conclude that the volume of oxygen at STP required to react completely 
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