No question................................

In the 18th century, Italian biologist Lazzaro Spallanzani designed an experiment supporting the hypothesis that gastric juices

AURORKA [14]

Stomach ulcers, I've read it online and I take the test

7 0

2 years ago

Read 2 more answers

At a certain temperature, Kc = 0.0500 and ∆H = +39.0 kJ for the reaction below, 2 MgCl2(s) + O2(g) → 2MgO(s) + Cl2(g) Calculate

Minchanka [31]

Explanation:

Since, it is shown that the reaction has been reversed. Therefore, value of $K_{c}$ will become $\frac{1}{K_{c}}$ .

Hence, new $K_{c'} = \frac{1}{K_{c}}$

= $\frac{1}{0.0500}$

= 20

Also, the number of moles of each reactant has been halved. So, $K_{c''}$ for the reaction $MgO(s) + \frac{1}{2}Cl2(g) → MgCl_{2}(s) + \frac{1}{2} O2(g)$ will also get halved.

Therefore, $K_{c''}$ = $K_{c'}$ = $(20)^{0.5}$

= 4.47

As the value of $\Delta H$ is given as +39.0 kJ. So, it means that the reaction is endothermic in nature. So, energy of reactants will be more than the products. Hence, according to Le Chatelier's principle reaction will move in the forward direction.

As a result, $K_{c}$ will also increase with increase in temperature.

6 0

3 years ago

Following the instructions in your lab manual, you have titrated a 25.00 mL sample of 0.0100 M KIO3 with a solution of Na2S2O3 o

vivado [14]

Answer:

For 1: The amount of potassium iodate that were titrated is $2.5\times 10^{-4}$ moles

For 2: The amount of sodium thiosulfate required is $1.25\times 10^{-4}$ moles

Explanation:

For 1:

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in L)}}$

Molarity of $KIO_3$ solution = 0.0100 M

Volume of solution = 25 mL

Putting values in above equation, we get:

$0.0100M=\frac{\text{Moles of }KIO_3\times 1000}{25}\\\\\text{Moles of }KIO_3=\frac{0.0100\times 25}{1000}=0.00025mol$

Hence, the amount of potassium iodate that were titrated is $2.5\times 10^{-4}$ moles

For 2:

The chemical equation for the reaction of potassium iodate and sodium thiosulfate follows:

$2KIO_3+Na_2S_2O_3\rightarrow K_2S_2O_3+2NaIO_3$

By Stoichiometry of the reaction:

2 moles of potassium iodate reacts with 1 mole of sodium thiosulfate

So, 0.00025 moles of potassium iodate will react with = $\frac{1}{2}\times 0.00025=0.000125mol$ of sodium thiosulfate

Hence, the amount of sodium thiosulfate required is $1.25\times 10^{-4}$ moles

6 0

3 years ago

What is the pH of a solution with [H+]=6.2x10-9 M?

Serga [27]

Answer: 8.2

Explanation:

pH of a solution is - Log [ H+].

pH = - Log [ 6.2 x 10-9 M]

= 9 - 0.7924

pH = 8.24 approx 8.2

3 0

3 years ago

Calculate the number of moles of magnesium, chlorine, and oxygen atoms in 7.80 moles of magnesium perchlorate, Mg(ClO4)2.

Dmitry [639]

The number of moles of moles of Magnesium,chlorine and oxygen atoms in 7.80 moles of Mg(ClO4)2 is calculated as below

find the total number of each atom in Mg(ClO4)2

that is mg = 1 atom
Cl = 1x2 = 2 atoms
O = 4 x2 = 8 atoms

then multiply 7.80 moles with total number of each atom , to get the number moles of each atom
that is

Mg = 7.80 x1= 7.80 moles
cl = 7.80 x2=15.6 moles
O = 7.80 x8= 62.4 moles

5 0

3 years ago