Percent by mass of an element can be calculated as
(Total mass of the element in the formula / formula weight ) * 100
Step 1 : Find formula weight of NaHCO₃
To find formula weight of NaHCO₃, we have to add atomic masses of the elements Na, H,C and O
Formula weight of NaHCO₃ = 
Formula weight of NaHCO₃ = 
Formula weight of NaHCO₃ is 84.01 g
Step 2 : Use percent by mass formula
Percent by mass of oxygen = (total mass of oxygen / formula weight) * 100
Percent by mass of oxygen = 
Percent by mass of oxygen = 57.14%
Answer : percentage by mass of oxygen in a formula unit of sodium hydrogen carbonate (NaHCO3) is 57.14%
Each chemical reaction, you may say that there are many possible balanced reactions since the coefficients of the reactants and of the products can be another set of numbers as long as the ratios of the compounds would be the same. The most preferred balanced reaction would be the reaction which have the lowest value of coefficients. Example would be the reaction of HCl and NaOH.
HCl + NaOH = NaCl + H2O (This would be the most preferred one since the coefficients are in the lowest value)
Other equivalents would be:
2HCl + 2NaOH = 2NaCl + 2H2O
3HCl + 3NaOH = 3NaCl + 3H2O
4HCl + 4NaOH = 4NaCl + 4H2O
I believe D has the largest radius out of the other 3.
<span>The number of moles in Al2O3 is .16575 moles</span>
Answer:
Magnesium Nitrate is an ionic compound formed by:
Magnesium;Mg+2 (<em>the cation)</em> and Nitrate NO−3 (<em>the poly-atomic anion)</em>.
In order for these two ions to bond, the charges must be equal and opposite. Therefore, it will take:
<u>two -1 nitrate ions</u> <u>to balance the</u> <u>one +2 magnesium ion</u>.