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3 years ago

How many moles of KNO3 are needed to make 600 ml of a 1.3M solution?

1 answer:

7 0

M = n / V

Where, M is molarity (M or mol/L), n is number of moles of the solute (mol) and V is volume of the solution (L).

Here the solute is KNO₃.
The given molarity is 1.3 M
This means 1L of solution has 1.3 moles of KNO₃.

Hence moles in 600 mL = 1.3 M x 0.6 L = 0.78 mol

Therefore to make 1.3 M KNO₃ solution, needed moles of KNO₃ is 0.78 mol

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Consider the following reaction at constant P. Use the information here to determine the value of Î”Ssurr at 355 K. Predict whet

Sloan [31]

The given reaction is as follows:

2NO (g) + O₂ (g) = 2NO₂ (g), ΔH = -114 kJ

It is known that dSsurr = -dHsys / T (Temp = 355 K)

So, dSsurr = - (-114 × 1000) / 355

dSsurr = +321.12 J/K

Hence, the value of dSsurr is +321.12 J/K

For a reaction to be spontaneous, dG<0,

Also dStotal = dSsys + dSsurr > 0

It is known that dG = dHsys - TdSsys,

Now let us assume,

dG<0

Also, dStotal = dSsys + dSsurr > 0

(-114 × 1000) - (355 × dSsys) <0

355 × dSsys > -114 × 1000

dSsys > -321

dSsys >dSsurr

dSsys + dSsurr > 0

dStotal > 0

Thus, the assumption is correct, and the given reaction is spontaneous. Hence, the final answer is Ssurr = +321 J/K reaction is spontaneous.

8 0

3 years ago

What is not represented by a balanced chemical equation?

astraxan [27]

Answer is: 4) The same subscripts are on each side of the equation.

For example, balanced chemical reaction:

2Mg + O₂ → 2MgO.

1) The same number of atoms is on each side of the equation: two magnesium atoms and two oxgen atoms.

2) The formulas for all substances are correct: in magnesium oxide (MgO), magnesium has oxidation number +2 and oxygen -2, so formula is good, because compound must be neutral.

3) The same mass is represented on each side of the equation: because there is same number of atoms, the mass is the same.

4) The same subscripts are on each side of the equation: oxygen does not have same subscripts.

5 0

3 years ago

Calculate the pH at of a 0.10 Msolution of anilinium chloride . Note that aniline is a weak base with a of . Round your answer t

notsponge [240]

The question is incomplete, here is the complete question:

Calculate the pH at of a 0.10 M solution of anilinium chloride $(C_6H_5NH_3Cl)$ . Note that aniline $(C6H5NH2)$ is a weak base with a $pK_b$ of 4.87. Round your answer to 1 decimal place.

Answer: The pH of the solution is 5.1

Explanation:

Anilinium chloride is the salt formed by the combination of a weak base (aniline) and a strong acid (HCl).

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

$pH=7-\frac{1}{2}[pK_b+\log C]$

where,

$pK_b$ = negative logarithm of weak base which is aniline = 4.87

C = concentration of the salt = 0.10 M

Putting values in above equation, we get:

$pH=7-\frac{1}{2}[4.87+\log (0.10)]\\\\pH=5.06=5.1$

Hence, the pH of the solution is 5.1

8 0

3 years ago

Calculate the ph of a solution obtained by mixing 100ml each of 0.1M HCL, 0.1M HNO3 and 0.1M NaOH solutions.

Volgvan

Given:

Volume of each of the solutions = 100 mL of each
Concentration of HCl = 0.10 M
Concentration of HNO3 = 0.10 M
Concentration of NaOH = 0.10 M

If all are mixed in one solution, the pH will surely be low since there are two acids mixed with one base. The pH range should be 1 - 5.

7 0

3 years ago

Help quick!!!!!!

Tamiku [17]

The law of conservation of energy states that energy cannot be created or destroyed but can be converted or transferred. So when you're eating a burger which has chemical energy, it is transferred to mechanical energy if you go out and ride a bicycle. Another example is when the Sun which is thermal energy shines on the apple tree, it is converted to chemical energy because the apple has chemical energy. Transferred is pretty similar.

3 0

3 years ago