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3 years ago

HELP!! b. At the equivalence point, all of the acid has been neutralized by the base. Why does the pH change so

1 answer:

3 0

At equivalence there is no more HA and no more NaOH, for this particular reaction. So that means we have a beaker of NaA and H2O. The H2O contributes 1 x 10-7 M hydrogen ion and hydroxide ion. But NaA is completely soluble because group 1 ion compounds are always soluble. So NaA breaks apart in water and it just so happens to be in water. So now NaA is broken up. The Na+ doesn't change the pH but the A- does change the pH. Remember that the A anion is from a weak acid. That means it will easily attract a hydrogen ion if one is available. What do you know? The A anion is in a beaker of H+ ions! So the A- will attract H+ and become HA. When this happens, it leaves OH-, creating a basic solution, as shown below.

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Kc = 3.07 x 10-4 at 24°C for 2NOBr(g) ↔ 2NO(g) + Br2(g). If the initial concentration of NOBr = 0.878 M, what is the equilibrium

pav-90 [236]

Answer:

The equilibrium concentration of NO is 0.02124 M.

Explanation:

Given that,

Initial concentration of NOBr = 0.878 M

$k_{c}=3.07\times10^{-4}$

Temperature = 24°C

We know that,

The balance equation is

$2NOBr\Rightarrow 2NO+Br_{2}$

Initial concentration is,

$0.878\Rightarrow 0+0$

Concentration is,

$-2x\Rightarrow 2x+x$

Equilibrium concentration

$0.878-2x\Rightarrow 2x+x$

We need to calculate the value of x

Using formula of concentration

$k_{c}=\dfrac{[NO][Br_{2}]}{[NOBr]^2}$

Put the value into the formula

$3.07\times10^{-4}=\dfrac{[2x][x]}{[0.878-2x]^2}$

$2x^2=3.07\times10^{-4}\times(0.878)^2+3.07\times10^{-4}\times4x^2-2\times2x\times0.878\times3\times10^{-4}$

$2x^2=0.0002367+0.001228x^2-0.0010536x$

$2x^2-0.001228x^2+0.0010536x-0.0002367=0$

$1.998772x^2+0.0010536x-0.0002367=0$

$x=0, 0.01062$

We need to calculate the equilibrium concentration of NO

Using formula of concentration of NO

$concentration\ of\ NO=2x$

Put the value of x

$concentration\ of\ NO=2\times0.01062$

$concentration\ of\ NO=0.02124$

Hence, The equilibrium concentration of NO is 0.02124 M.

7 0

3 years ago

5.80 gg of NaCl in 350. mL of a NaClsolution

Delicious77 [7]

Answer:

Solution is 0.28 M

You can also say, [NaCl] = 0.28 mol/L

Explanation:

As you have a solute mass and the solution's volume, you may find the molarity concentration of solution.

Molarity specifies the moles of solute in 1 L of solution

We convert the volume of solution to L → 350 mL . 1L / 1000 mL = 0.350L

We convert the mass of solute to moles → 5.80 g . 1mol / 58.45 g = 0.0992 moles

Molarity (mol/L) = 0.0992 mol /0.350L = 0.28M

6 0

2 years ago

WILL MARK BRAINLY! Which chemical element has the shortest name?

Aleonysh [2.5K]

Answer:

boron I guess

hope this heps

5 0

2 years ago

Why does galium melt

levacccp [35]

Answer:

Like most other metals, Gallium is solid at room temperature (or liquid if it is too hot in your room). But, if it is held [in hands] for long enough, it melts in your hands, and doesn't poison you like Mercury would. This is because of its unusually low melting point of (~29 degree Centigrade).

- It melts once it reaches its melting point.

7 0

2 years ago

Which classification best describes oxygen gas? a element b compound c solution d heterogeneous mixture

NNADVOKAT [17]

Answer:

oxygen is an element because it is a pure substance which cannot be split into simpler substances by chemical means

4 0

3 years ago