Answer:
6.02 x 10²⁰ molecules
Explanation:
Given parameters:
Volume of nitrogen = 120cm³
Unknown:
Mass of Nitrogen = ?
Number of molecules present in it = ?
Solution:
At STP;
1 mole of a substance contains 22.4dm³ particles
100cm³ = 1dm³
24cm³ will give 0.024dm³
22.4dm³ of particles are in 1 mole of substances at STP
0.024dm³ of particles will contain 
= 0.001mole
Mass of Nitrogen = Number of moles x molar mass
molar mass of nitrogen = 14g/mol
Mass of nitrogen = 0.001 x 14 = 0.014g
Number of molecules present;
1 mole of a substance contains 6.02 x 10²³ molecules
0.001 mole of Nitrogen will contain 0.001 x 6.02 x 10²³ = 6.02 x 10²⁰
6.02 x 10²⁰ molecules
Answer:
Increase in the concentration of the reactants (vinegar and baking soda) leads to an increase in the rate of reaction (more volume of CO2 is evolved within a shorter time)
Explanation:
The chemical reaction between baking soda and vinegar in water is shown in the chemical reaction equation below;
NaHCO3(aq) + CH3COOH(aq) ----->CO2(g) + H2O(l) + CH3COONa(aq)
The chemical name of baking soda is sodium bicarbonate (NaHCO3) while vineager is a dilute acetic acid (CH3COOH) solution. This reaction provides a very easy set up in which we can study the effect of concentration on the rate of chemical reaction.
We must have it behind our minds that increase in the concentration of reactant species increases the rate of chemical reaction. Secondly, the rate of the reaction between baking soda and vinegar can be monitored by observing the volume of CO2 evolved and how quickly it evolves from the reaction mixture.
We can now postulate a hypothesis which states that; 'increase in the concentration of the reactants (vinegar and baking soda) leads to an increase in the rate of reaction (more volume of CO2 is evolved within a shorter time).'
If we go ahead to subject this hypothesis to experimental test, it will be confirmed to be true because a greater volume of CO2 will be evolved within a shorter time as the concentration of the reactants increases.
A. <span>Sodium is oxidized and chlorine is reduced.</span>
