All categories

3 years ago

What’s in the gaps...

Chemistry

1 answer:

coldgirl [10]3 years ago

8 0

Answer:

Faster

number

reactants

increases

Explanation:

The rate of reaction refers to how fast or slow a reaction occurs. The rate of reaction is dependent on factors such as surface area, concentration, temperature, nature of reactants, catalyst etc.

The concentration refers to the amount of reactants present. When the acid is made more concentrated, its amount is increased. This increases the number of collisions between the acid particles and the marble chips ultimately leading to increase in the rate of reaction according to Arrhenius theory.

You might be interested in

3 A partial desert food web is shown.

Fofino [41]

Decomposeza is correct

8 0

3 years ago

5. The statement that in undisturbed sedimentary rock layers,

Colt1911 [192]

Answer:

The correct answer is - option C. Law of superposition.

Explanation:

According to the law of superposition states that within a sequence of layers of natural sedimentary rock without any disturbance, the oldest layer is lies under the younger layers with ascending order in the sequence.

If a sedimentary rock has 4 layers as a, b, c and d where the younger layer d would be on top and the oldest layer a would be at the bottoms.

Thus, the correct answer is - option C.

7 0

3 years ago

Read 2 more answers

Are the following Physical or Chemical changes?

AveGali [126]

1- physical
2-chemical
3-Physical
4-Chemical
5-I’m not sure
I haven’t done this in a while so these may be wrong sorry

6 0

4 years ago

A chemist fills a reaction vessel with 9.20 atm nitrogen monoxide (NO) gas, 9.15 atm chlorine (CI) gas, and 7.70 atm nitrosyl ch

ivanzaharov [21]

Answer:

The reactions free energy $\Delta G = -49.36 kJ$

Explanation:

From the question we are told that

The pressure of (NO) is $P_{NO} = 9.20 \ atm$

The pressure of (Cl) gas is $P_{Cl} = 9.15 \ atm$

The pressure of nitrosly chloride (NOCl) is $P_{(NOCl)} = 7.70 \ atm$

The reaction is

$2NO_{(g)} + Cl_2 (g)$ ⇆ $2 NOCl_{(g)}$

From the reaction we can mathematically evaluate the $\Delta G^o$ (Standard state free energy ) as

$\Delta G^o = 2 \Delta G^o _{NOCl} - \Delta G^o _{Cl_2} - 2 \Delta G^o _{NO}$

The Standard state free energy for NO is constant with a value

$\Delta G^o _{NO} = 86.55 kJ/mol$

The Standard state free energy for $Cl_2$ is constant with a value

$\Delta G^o _{Cl_2} = 0kJ/mol$

The Standard state free energy for $NOCl$ is constant with a value

$\Delta G^o _{NOCl} =66.1kJ/mol$

Now substituting this into the equation

$\Delta G^o = 2 * 66.1 - 0 - 2 * 87.6$

$= -43 kJ/mol$

The pressure constant is evaluated as

$Q = \frac{Pressure \ of \ product }{ Pressure \ of \ reactant }$

Substituting values

$Q = \frac{(7.7)^2 }{(9.2)^2 (9.15) } = \frac{59.29}{774.456}$

$= 0.0765$

The free energy for this reaction is evaluated as

$\Delta G = \Delta G^o + RT ln Q$

Where R is gas constant with a value of $R = 8.314 J / K \cdot mol$

T is temperature in K with a given value of $T = 25+273 = 298 K$

Substituting value

$\Delta G = -43 *10^{3} + 8.314 *298 * ln [0.0765]$

$= -43-6.36$

$\Delta G = -49.36 kJ$

4 0

3 years ago

What is the edge length of a face-centered cubic unit cell made up of atoms having a radius of 175 pm

SVEN [57.7K]

Answer:

495 pm (see the relationship between the edge length (a) and radius (r) of atoms in attachment).

Explanation:

A crystalline solid possess rigid and long-range order; its atoms, molecules, or ions occupy specific positions. A unit cell is the basic repeating structural unit of a crystalline solid. Each sphere in the unit cell represents an atom, ion, or molecule and is called a lattice point. The way the spheres are arranged in layers determines what type of unit cell we have.

In the face-centered cubic cell, there are spheres at the center of each of the six faces of the cube, in addition to the eight corner spheres (see the second picture in the attachment). Each sphere in this arrangement is said to have a coordination number of 12 since each sphere is in contact with six spheres in its own layer, three spheres in the layer above, and three spheres in the layer below. The coordination number is defined as the number of atoms (or ions) surrounding an atom (or ion) in a crystal lattice.

In the first picture in the attachment we can see that the relationship between the atomic radius r and the edge length a face-centered cubic cell is:

a=√8*r

Therefore, the edge length will be √8*175 pm = 495 pm

8 0

3 years ago