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2 years ago

a neutral aluminum atom has a mass number of 27 an atomic number of 13 and a charge of 0. how many neutrons does it have

Chemistry

1 answer:

Nastasia [14]2 years ago

8 0

Answer:

14 neutrons

Explanation:

Mass - Atomic Number = Neutrons

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Balance the equation __Ni(CIO)3 → _NiCl2+ _02

lora16 [44]

The answer is 1, 1 , 1 because that will balance out the equation and make them equal

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3 years ago

Which adaptation helps a tapeworm attach itself to the intestines of its host?

lubasha [3.4K]

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B) hooks and suck- ers

Explanation:

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3 years ago

Read 2 more answers

A buffer solution contains 0.306 M C6H5NH3Br and 0.418 M C6H5NH2 (aniline). Determine the pH change when 0.124 mol HCl is added

Ulleksa [173]

Answer: The pH change of the buffer is 0.30

Explanation:

To calculate the pH of basic buffer, we use the equation given by Henderson Hasselbalch:

$pOH=pK_b+\log(\frac{[\text{conjugate acid}]}{[\text{base}]})$

$pOH=pK_b+\log(\frac{[C_6H_5NH_3^+]}{[C_6H_5NH_2]})$ .....(1)

We are given:

$pK_b$ = negative logarithm of base dissociation constant of aniline = 9.13

$[C_6H_5NH_3^+]=0.306M$

$[C_6H_5NH_2]=0.418M$

pOH = ?

Putting values in equation 1, we get:

$pOH=9.13+\log(\frac{0.306}{0.418})\\\\pOH=8.99$

To calculate pH of the solution, we use the equation:

$pH+pOH=14\\pH_{initial}=14-8.99=5.01$

To calculate the molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Moles hydrochloric acid solution = 0.124 mol

Volume of solution = 1 L

Putting values in above equation, we get:

$\text{Molarity of HCl}=\frac{0.124}{1L}\\\\\text{Molarity of HCl}=0.124M$

The chemical reaction for aniline and HCl follows the equation:

$C_6H_5NH_2+HCl\rightarrow C_6H_5NH_3^++Cl^-$

Initial: 0.418 0.124 0.306

Final: 0.294 - 0.430

Calculating the pOH by using using equation 1:

$pK_b$ = negative logarithm of base dissociation constant of aniline = 9.13

$[C_6H_5NH_3^+]=0.430M$

$[C_6H_5NH_2]=0.294M$

pOH = ?

Putting values in equation 1, we get:

$pOH=9.13+\log(\frac{0.430}{0.294})\\\\pOH=9.29$

To calculate pH of the solution, we use the equation:

$pH+pOH=14\\pH_{final}=14-9.29=4.71$

Calculating the pH change of the solution:

$\Delta pH=pH_{initial}-pH_{final}\\\\\Delta pH=5.01-4.71=0.30$

Hence, the pH change of the buffer is 0.30

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3 years ago

What best explains the type of energy present in the vibrating atoms of a substance

luda_lava [24]

The type of energy present in the vibrating atoms of a substance is a thermal energy and it is a kinetic type of energy. It is associated with movement within the crystal lattice of substance. ... Eventually, it can lead to motion of the atoms which is a form of kinetic energy.

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3 years ago

The arrows below represent the velocities of two vehicles. Which claim explains why the velocity of each vehicle is a vector qua

ollegr [7]

Answer:

It has direction and size.

Explanation:

All physical quantities are generally grouped into two;

i) Vector quantities

ii) Scalar quantities

Vector quantities are those quantities that has both magnitude (size) and direction.

Scalar quantities are those quantities that has magnitude (size) and no direction.

Velocity is a vector quantity because it has direction and size.

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2 years ago