Answer:
Option A.
2Na + 2H2O —> 2NaOH + H2
Explanation:
To know which option is correct, we shall do a head count of the number of atoms present on both side to see which of them is balanced. This is illustrated below below:
For Option A:
2Na + 2H2O —> 2NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 2 Na
4 H >>>>>>>>>>>> 4 H
2 O >>>>>>>>>>>> 2 O
Thus, the above equation is balanced.
For Option B:
2Na + 2H2O —> NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 1 Na
4 H >>>>>>>>>>>> 3 H
2 O >>>>>>>>>>>> 1 O
Thus, the above equation is not balanced.
For Option C:
2Na + H2O —> 2NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 2 Na
2 H >>>>>>>>>>>> 4 H
1 O >>>>>>>>>>>> 2 O
Thus, the above equation is not balanced.
For Option D:
Na + 2H2O —> NaOH + 2H2
Reactant >>>>>>> Product
1 Na >>>>>>>>>>> 1 Na
4 H >>>>>>>>>>>> 5 H
2 O >>>>>>>>>>>> 1 O
Thus, the above equation is not balanced.
From the illustrations made above, only option A is balanced.
Answer:
0.914moles
Explanation:
The number of moles in a substance can be got by dividing the number of atoms/molecules/particles by Avagadro's constant (6.02 × 10^23).
That is;
number of moles (n) = number of atom (nA) ÷ 6.02 × 10^23
According to this question, there are 5.5 x 10-23 molecules of H2O
n = 5.5 x 10^23 ÷ 6.02 × 10^23
n = 0.914 × 10^(23-23)
n = 0.914 × 10^0
n = 0.914 × 1
n = 0.914moles
10 seconds = 8grams
then just divide by 2 another 4 times...
= 0.5grams after 50 seconds
Heterogenous mixtures can separates due to differences in size of components
Answer:
<h2>The answer is 3.0 mL</h2>
Explanation:
The volume of a substance when given the density and mass can be found by using the formula
From the question
mass of aluminum = 8.1 g
density = 2.7 g/mL
It's volume is
We have the final answer as
<h3>3.0 mL</h3>
Hope this helps you
