Answer:
Increase in CO2 (g) over time.
No NaHCO3 (s) will be left after a time
Explanation:
The reaction, shown below;
2NaHCO3(s) → Na2CO3(s)+CO2(g)+H2O(ℓ) is a decomposition reaction. A decomposition reaction is a kind of chemical reaction in which a given chemical specie breaks up to give other chemical species. Decomposition may be induced by heat or light.
Usually, there is only one reactant in a decomposition reaction; the specie that disintegrates into the products. This reactant usually decreases in concentration steadily because it is converted into products. This is why the mass of NaHCO3(s) in the system continues to decrease steadily until it finally falls to zero.
Conversely, the concentration (for aqueous) or volume (for gases) or mass (for solid) products of the reaction increases steadily as the reaction progresses. This explains why the volume of CO2 in the system will steadily increase over time.
c. the answer is radioactive elements are useful for dating materials
An active skill of information from a primary source
Answer:
We need 0.68 moles of aluminium ions to be present to make 0.34 moles Al2(SO4)3
Explanation:
Step 1: Data given
Number of moles Al2(SO4)3 = 0.34 moles
Step 2: The balanced equation
2Al + 3H2SO4 = Al2(SO4)3 + 3H2
Step 3: Calculate the number of moles aluminium ions
For 2 moles we need 3 moles H2SO4 to produce 1 mol Al2(SO4)3 and 3 moles H2
For 0.34 moles Al2(SO4)3 we need 2*0.34 = 0.68 moles aluminium
We need 0.68 moles of aluminium ions to be present to make 0.34 moles Al2(SO4)3
