For which of the following reactions is ΔH∘rxn equal to ΔH∘f of the product(s)?

In an experiment, hydrochloric acid reacted with different volumes of sodium thiosulfate in water. A yellow precipitate was form

morpeh [17]

Answer:

The time taken for the cross to become invisible decreases.

Explanation:

We know that one of the factors affecting the rate of reaction is the concentration of reactants. From the collision theory, we know that the higher the concentration of reactants, the greater the possibility of effective collision between reactants leading ultimately to an increase in the rate of reaction. Increase in the rate of reaction implies that the reaction takes a shorter time to reach completion.

In the case of the reaction shown in the question, the point when the reaction is completed is observed by the time take for the cross mark to become invisible. If we look at the given data closely, we will notice that the volume of acid was held constant, the volume of thiosulphate was increased gradually while the volume of water was decreased accordingly. This implies that the concentration of the reactants was increased. Decreasing the volume of water increases reactant concentration.

As explained above, increase in reactant concentration increases the rate of reaction. Hence, the rate of reaction of the acid and thiosulphate increases as reactant concentration increases and the cross mark becomes invisible faster. This implies that in the last column for time taken for the cross to become invisible, the values of time decreases steadily as concentration of reactants increases.

5 0

3 years ago

Calculate the silver ion concentration in a saturated solution of silver(i) sulfate (ksp = 1.4 × 10–5).

deff fn [24]

Answer:

= 0.030 M

Explanation:

We can take x to be the concentration in mol/L of Ag2SO4 that dissolves

Therefore; concentration of Ag+ is 2x mol/L and that of SO4^2- x mol/L.

Ksp = 1.4 x 10^-5

Ksp = [Ag+]^2 [SO42-]

= (2x)^2(x)

= 4x^3

Thus;

4x^3 = 1.4 x 10^-5

= 0.015 M

molar solubility = 0.015 M

But;

[Ag+]= 2x

Hence; silver ion concentration is

= 2 x 0.015 M

= 0.030 M

6 0

2 years ago

True or false: Some parasites are able to change the behavior of their host, which often helps the parasite complete some part o

anzhelika [568]

It’s trueeeeee for the answer

3 0

2 years ago

600 s after initiation of a first order reaction 48.5% of the initial reactant concentration remains present. What is the rate c

Ludmilka [50]

Answer:

$k=1.20x10^{-3} s^{-1}$

Explanation:

For a first order reaction the rate law is:

$v=\frac{-d[A]}{[A]}=k[A]$

Integranting both sides of the equation we get:

$\int\limits^a_b {\frac{d[A]}{[A]}} \, dx =-k\int\limits^t_0 {} \, dt$

where "a" stands for [A] (molar concentration of a given reagent) and "b" is {A]0 (initial molar concentration of a given reagent), "t" is the time in seconds.

From that integral we get the integrated rate law:

$ln\frac{[A]}{[A]_{0} } =-kt$