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3 years ago

The reaction A → products is first-order in A. If the concentration of A is cut in half, the half-life of the reaction will

Chemistry

1 answer:

Andru [333]3 years ago

4 0

Answer:

c. remain constant.

Explanation:

The half life is defined as the time at which the reactant's concentration reduced to half.

The formula for the half life for a first order kinetic reaction is:

$t_{1/2}=\frac {ln\ 2}{k}$

Where,

$t_{1/2}$ is the half life

k is the rate constant.

As seen from the formula the half life for a first order reaction is independent of the reactant's concentration.

So, it will remain constant on any change of the reactant's concentration.

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If 125 g of CaCO3 is mixed and reacted with 125 g of HCl, which reactant is limiting and how many grams of CO2 can be made?

Trava [24]

Answer:

CaCO3 is the limiting reactant

55 g of CO2 is made

Explanation:

First we must put down the reaction equation;

CaCO3(s) + 2HCl(aq) ---------> CaCl2(s) + H2O(l) + CO2(g)

Number of mole of CaCO3 = 125g/100gmol-1 = 1.25 moles

From the reaction equation;

1 mole of CaCO3 yields 1 mole of CO2

Hence 1.25 moles of CaCO3 yields 1.25 moles of CO2

For HCl;

number of moles of HCl = 125g/36.5 g mol-1 = 3.42 moles

From the reaction equation;

2 moles of HCl yields 1 mole of CO2

3.42 moles of HCl yields 3.42 * 1/2 = 1.71 moles of CO2

Hence CaCO3 is the limiting reactant.

Mass of CO2 produced = 1.25g * 44 gmol-1 = 55 g of CO2

6 0

3 years ago

Calculate the moles of SO₂ produced when 5 moles of FeS₂ reacts according to the equation: 4FeS₂+ 11O₂ → 2Fe₂O₃ + 8SO₂

Gala2k [10]

Answer:

10 moles of SO₂ are produced when 5 moles of FeS₂

Explanation:

Stoichiometry: it is the theoretical proportion in which the chemical species are combined in a chemical reaction. The stoichiometric equation of a chemical reaction relates molecules or number of moles of all the reagents and products that participate in the reaction.

In other words, stoichiometry establishes relationships between the molecules or elements that make up the reactants of a chemical equation with the products of said reaction. The relationships established are molar relationships (that is, moles) between the compounds or elements that make up the chemical equation.

The stoichiometric coefficients of a chemical reaction indicate the proportion in which said substances react.

Taking into account the above, you can apply the following rule of three: by stoichiometry if 4 moles of FeS₂ produce 8 moles of SO₂, then when reacting 5 moles of FeS₂ how many moles of SO₂ will they produce?

$moles of SO_{2} =\frac{5 moles of FeS_{2} *8moles of SO_{2}}{4 moles of FeS_{2}}$

moles of SO₂= 10

10 moles of SO₂ are produced when 5 moles of FeS₂

7 0

3 years ago

Annie has a soccer ball and a kickball she kicks each ball with the same force the soccer ball accelerates at 3 m/s to the secon

Alexxandr [17]

Answer:

Because of less weight kick ball has more acceleration.

Explanation:

Acceleration of kick ball:

5 m/s

Acceleration of soccer ball:

3 m/s

Newton's second law:

According to newton's second law the acceleration of object depends upon two variables.

1) Mass of object

2) Force acting on it

Mathematical expression:

a = f/m

a = acceleration

f = force

m = mass

The force on balls are same thus the acceleration is depend upon the masses of balls.

The soccer ball has more weight that's why its acceleration is less while kick ball is lighter and thus its acceleration will more.

8 0

3 years ago

A piece of copper has a mass of 660 g. How many atoms does the sample contain?

son4ous [18]

The conversions that will be used are:

1 mole of copper / 63.5 grams of copper
6.02 x 10²³ atoms of copper / 1 mole of copper

Multiplying the given mass by these conversions,

660 g * (1 mol Cu / 63.5 g Cu) * (6.02 x 10²³ Cu atoms / 1 mole Cu)

The sample contains 6.25 x 10²⁴ atoms of copper

4 0

3 years ago

What is the transmittance of 35.3%

andrey2020 [161]

This might be wrong,but im pretty sure its 0.10 m

8 0

3 years ago