1. Which of the following does NOT indicate that a chemical change may have taken place?

At 700 K, the reaction below has an Kp value of 54. An equilibrium mixture at this temperature was found to contain 0.933 atm of

kati45 [8]

Answer:

See explanation below

Explanation:

In this case, we have the equilibrium reaction which is:

H₂ + I₂ <------> 2HI Kp = 54

Now, we have the partial pressures of each element in equilibrium, therefore, we can use the expression of equilibrium in this case to calculate the remaining pressure:

Kp = PpHI² / PpH₂ * PpI₂

Solving for the partial pressure of iodine:

PpI₂ = PpHI² / PpH₂ * Kp

Replacing the given values, we have:

PpI₂ = (2.1)² / 0.933 * 54

PpI₂ = 4.41 / 50.382

PpI₂ = 0.088 atm

4 0

3 years ago

A sample was then prepared containing 14.00 mL of coffee and 8.00 mL of 4.80 ppm Li , and diluted to a 50.00 mL total volume. Th

mafiozo [28]

Answer:

The right answer is " $[Na^+]=5.57 \ ppm$ ".

Explanation:

The given values are:

$\frac{A_s}{A_{coffee}} =\frac{0.840}{1.000}$

According to the question,

The concentration of standard will be:

= $\frac{7.80}{50.00}\times 4.80$

= $0.156\times 4.80$

= $0.748 \ ppm$

Coffee after dilution,

⇒ $\frac{A_{coffee}}{C_{coffee}} =F\times \frac{A_s}{C_s}$

or,

⇒ $C_{coffee}=\frac{A_{coffee}}{A_s}\times \frac{C_s}{F}$

On substituting the values, we get

⇒ $=\frac{1.000}{0.840}\times \frac{0.748}{1.68}$

⇒ $=1.191\times 1.3104$

⇒ $=1.561 \ ppm$

hence,

In unknown sample, the concentration of coffee will be:

= $1.561\times \frac{50}{14}$

= $\frac{78.05}{14}$

= $5.57 \ ppm$

7 0

3 years ago

Which of the following are true about Earth’s axis. Choose the two correct answers.

Citrus2011 [14]

Answer:

B and D

Explanation:

4 0

3 years ago

Which type of preservation is made when a mold fills in with sediment, showing the exterior features of an organism?

Sever21 [200]

That would be C, a cast. It is similar to the process of filling a mold with foam or clay, which is also called a cast.

5 0

3 years ago

Read 2 more answers

If one gram of sulphur dioxide contains x molecules what will be the number of molecules in 1g of methane

evablogger [386]

The ratio of molecules in sulphur dioxide and methane will be the same as the ratio of their moles. So, first of all we should find out the number of moles of sulphur dioxide in 1 gram of sulphur dioxide in 1 gram of sulphur dioxide, and the number of moles of methane in 1 gram of methane. This can be done as follows :

(i) The molecular formula of sulphur dioxide is $SO_{2}$

So, $1$ mole of $SO_{2}$ = $Mass$ $of$ $2'O'$

$=32+2*16$

$= 64$ grams

Now, $64g$ of sulphur dioxide $= 1$ mole

So, $1g$ of sulphur dioxide = $\frac{1}{64}$ mole

Thus, we have $\frac{1}{64}$ mole of sulphur dioxide and it contains molecules in it. Now, since equal moles of all the substance contain equal number of molecules, therefore, $\frac{1}{64}$ mole of methane will also contain x molecules of methane.

(ii) Molecular formula of methan is $CH_{4}$