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:
Explanation:
I think you meant a covalent bond, a bond between two non-metal atoms. This image can explain better than I can.
The question here is solved using basic chemistry. CaCl2(aq) is an ionic compound which will have the releasing of 2 Cl⁻ ions ions in water for every molecule of CaCl2 that dissolves.
CaCl2(s) --> Ca+(aq) + 2 Cl⁻(aq)
[Cl⁻] = 0.65 mol CaCl2/1L × 2 mol Cl⁻ / 1 mol CaCl2 = 1.3 M
The answer to this question is [Cl⁻] = 1.3 M
<span>69.3 g
First, determine the molar masses involved:
Atomic weight iron = 55.845
Atomic weight carbon = 12.0107
Atomic weight oxygen = 15.999
Molar mass Fe2O3 = 2 * 55.845 + 3 * 15.999 = 159.687 g/mol
Molar mass CO = 12.0107 + 15.999 = 28.0097 g/mol
Determine how many moles of each reactant we have
Moles Fe2O3 = 189 g / 159.687 g/mol = 1.18356535 mol
Moles CO = 63.0 g / 28.0097 g/mol = 2.249220806 mol
For every mole of Fe2O3, we need 3 moles of CO. So let's see how many moles of Fe2O3 is consumed by dividing moles CO by 3.
2.249220806 mol / 3 = 0.749740269 mol
So we'll be consuming 0.749740269 moles of Fe2O3, subtract that from what we started with
1.18356535 mol - 0.749740269 mol = 0.433825081 mol
Now multiply by the molar mass of Fe2O3
0.433825081 mol * 159.687 g/mol = 69.27622574 g
Rounding to 3 significant figures gives 69.3 g</span>
Because the earth turns on a tilted axis (23.5° to be exact) Sometimes the top of the earth is facing the sun, and in December it's farthest away from the sun as it can be.
