Answer:
A horizontal line on a speed-time graph represents a constant speed. A sloping line on a speed-time graph represents an acceleration. The sloping line shows that the speed of the object is changing. The object is either speeding up or slowing down.
Answer: -
The rate decreases as the concentration of the reactants decreases
Explanation: -
A reaction involves change of the reactants into products.
Initially there is only reactants. So the rate if reaction is high.
After some time there are products. So the amount of reactant is less.
Reactions involve collisions of reactant molecules. As the reactant amount decreases, collisions between the reactants decreases. As such the rate of reaction decreases with the progress of the reaction.
0.250 mol/L
<em>Step 1</em>. Write the chemical equation
H2SO4 + 2NaOH → Na2SO4 + 2H2O
<em>Step 2</em>. Calculate the moles of H2SO4
Moles of H2SO4 = 12.5 mL H2SO4 × (0.500 mmol H2SO4/1 mL H2SO4)
= 6.25 mmol H2SO4
<em>Step 3</em>. Calculate the moles of NaOH
Moles of NaOH = 6.25 mmol H2SO4 × (2 mmol NaOH/(1 mmol H2SO4)
= 12.5 mmol NaOH
<em>Step 4</em>. Calculate the concentration of the NaOH
[NaOH] = moles/litres = 12.5 mmol/50.0 mL = 0.250 mol/L
