What pressure in atmospheres(atm) is equal to 45.6 kPa?

Barium-142 is used as a GI radiocontrast agent. After 1.25 hours, 9.25 μg remains in the patient. Determine the original dose gi

Trava [24]

Answer:

The answer to your question is the original dose of Ba-142 was 1184 μg

Explanation:

Data

Total time = 1.25 hours

The Final amount of Ba = 9.25 μg

The Half-life of Ba = 10.6 minutes

Process

1.- Convert total time to minutes

1 h ----------------- 60 min

1.25 h ------------ x

x = 75 min

2.- Draw a table of this process

Final amount of Ba Time

9.25 75 min

18.5 64.4 min

37 53.8 min

74 43.2 min

148 32.6 min

296 22 min

592 11.4 min

1184 0.8 min

4 0

3 years ago

What are the differences between amorphous and crystalline solids? Give an example of each.

Eddi Din [679]

Answer: orderly arrangement of particles

Explanation:

In a crystaline solid, the particles that compose the solid are arranged or packed in an orderly manner to form a three dimensional crystal lattice with a defined structure. Sodium chloride is a crystaline solid.

In an amorphous solid, the particles that compose the solid aren't arranged in an orderly manner hence the solid tends to be brittle, e.g glass

7 0

4 years ago

The water-gas shift reaction plays a central role in the chemical methods for obtaining cleaner fuels from coal: CO(g) + H2O(g)

taurus [48]

<u>Answer:</u> The concentration of carbon dioxide, hydrogen gas, carbon monoxide and water when equilibrium is re-established are 0.362 M, 0.212 M, 0.138 M and 0.138 M respectively.

<u>Explanation:</u>

For the given chemical reaction:

$CO(g)+H_2O(g)\rightleftharpoons CO_2(g)+H_2(g)$

The expression of $K_c$ for above reaction follows:

$K_c=\frac{[CO_2][H_2]}{[CO][H_2O]}$ ........(1)

We are given:

$[CO]_{eq}=[H_2O]_{eq}=[H_2]_{eq}=0.10M$

$[CO_2]_{eq}=0.40M$

Putting values in above equation, we get:

$K_c=\frac{0.40\times 0.10}{010\times 0.10}\\\\K_c=4$

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

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

Moles of hydrogen gas = 0.30 mol

Volume of solution = 2.0 L

Putting values in above equation, we get:

$\text{Molarity of }H_2=\frac{0.30mol}{2L}=0.15M$

When hydrogen gas is added, the concentration of product gets increased. But, by Le-Chatelier's principle, the equilibrium will shift in the direction where concentration of product must decrease, which is in the backward direction.

Concentration of hydrogen gas when equilibrium is re-established = 0.1 + 0.15 = 0.25 M

Now, the equilibrium is shifting to the reactant side. The equation follows:

$CO(g)+H_2O(g)\rightleftharpoons CO_2(g)+H_2(g)$

Initial: 0.1 0.1 0.4 0.1

At eqllm: 0.1+x 0.1+x 0.4-x 0.25-x

Putting values in expression 1, we get:

$4=\frac{(0.25-x)(0.4-x)}{(0.1+x)(0.1+x)}\\\\3x^2+1.45x-0.06=0\\\\x=0.038,-0.522$

Neglecting the negative value of 'x'

Calculating the concentrations of the species:

Concentration of carbon dioxide = (0.4 - x) = (0.4 - 0.038) = 0.362 M

Concentration of hydrogen gas = (0.25 - x) = (0.25 - 0.038) = 0.212 M

Concentration of carbon monoxide = (0.1 + x) = (0.1 + 0.038) = 0.138 M

Concentration of water = (0.1 + x) = (0.1 + 0.038) = 0.138 M

Hence, the concentration of carbon dioxide, hydrogen gas, carbon monoxide and water when equilibrium is re-established are 0.362 M, 0.212 M, 0.138 M and 0.138 M respectively.

8 0

4 years ago

How many atoms of lead are contained in 0.532mol?

Colt1911 [192]

Answer:

3.2043 x 10²³

Explanation:

No. of Mole of lead (Pb) = 0.532 mol

No. of atoms of lead = ?

Solution:

Formula Used to calculate

no. of moles = numbers of particles (ions, molecules, atoms) /Avogadro's number

Avogadro's no. = 6.023 x10²³

So,

The formula could be written as

no. of atoms of lead Pb = no. of moles x 6.023 x10²³

Put the values in above formula

no. of atoms of lead Pb = 0.532 mol x 6.023 x10²³

no. of atoms of lead Pb = 3.2043 x 10²³

so 3.2043 x 10²³ atoms of lead are contained in 0.532 mole.

6 0

3 years ago

What is the result of multiplying 2.55 x 10^10 m x 3.5 x 10^-7m using proper significant figures and scientific notation.

BartSMP [9]

3 I think I’m sure much love

3 0

3 years ago