The correct reference for this isotope is A. Oxygen-18.
Answer:
Importance of Phlogiston Theory . Although the theory has since been discarded, it's important because it shows the transition between alchemists believing in the traditional elements of earth, air, fire, and water, and true chemists, who conducted experimentation that led to the identification of true chemical elements and their reactions.
Explanation:
Answer:
630.95 grams of Na₂CO₃ would be needed to produce 1000g of NaHCO₃
Explanation:
The balanced reaction is:
Na₂CO₃ + CO₂+ H₂O → 2 NaHCO₃
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:
- Na₂CO₃: 1 moles
- CO₂: 1 mole
- H₂O: 1 mole
- NaHCO₃: 2 moles
Being the molar mass:
- Na₂CO₃: 106 g/mole
- CO₂: 44 g/mole
- H₂O: 18 g/mole
- NaHCO₃: 84 g/mole
Then by stoichiometry the following quantities of mass participate in the reaction:
- Na₂CO₃: 1 mole* 106 g/mole= 106 g
- CO₂: 1 mole* 44 g/mole= 44 g
- H₂O: 1 mole* 18 g/mole= 18 g
- NaHCO₃: 2 moles* 84 g/mole= 168 g
You can apply the following rule of three: if 106 grams of Na₂CO₃ are needed to produce 168 grams of NaHCO₃, how much mass of Na₂CO₃ is necessary to produce 1000 grams of NaHCO₃?

mass of Na₂CO₃= 630.95 grams
<u><em>630.95 grams of Na₂CO₃ would be needed to produce 1000g of NaHCO₃</em></u>
The concentration of volume of solution can be expressed in many ways for example: mass percent, volume percent, mass-by-volume percent, etc.
The formula for mass-by-volume percent is:
mass-by-volume percent = 
2% erythromycin solution means 2 g of erythromycin in 100 mL.
Consider, for 15 g the volume be X mL.
So,



Hence, the volume is
.