How many oxygen molecules are present in 113.97 liters of oxygen gas at stp?

Find [H+] of a 0.056 M hydrofluoric acid solution. Ka = 1.45 x 10-7

brilliants [131]

Answer: $[H^+]$ of 0.056 M HF solution is $8.96\times 10^{-5}$

Explanation:

$HF\rightarrow H^+F^-$

cM 0 0

$c-c\alpha$ $c\alpha$ $c\alpha$

So dissociation constant will be:

$K_a=\frac{(c\alpha)^{2}}{c-c\alpha}$

Give c= 0.056 M and $\alpha$ = ?

$K_a=1.45\times 10^{-7}$

Putting in the values we get:

$1.45\times 10^{-7}=\frac{(0.056\times \alpha)^2}{(0.056-0.056\times \alpha)}$

$(\alpha)=0.0016$

$[H^+]=c\times \alpha$

$[H^+]=0.056\times 0.0016=8.96\times 10^{-5}$

Thus $[H^+]$ of 0.056 M HF solution is $8.96\times 10^{-5}$

8 0

3 years ago

What is the Molar Mass of methylammonium bromide: Use the Periodic Table and round to the nearest hundredths.

egoroff_w [7]

The molar mass of methylammonium bromide is 111u.

<h3>What is molar mass?</h3>

The molar mass is defined as the mass per unit amount of substance of a given chemical entity.

Multiply the atomic weight (from the periodic table) of each element by the number of atoms of that element present in the compound.

Add it all together and put units of grams/mole after the number.

Atomic weight of H is 1u

Atomic weight of N is 14u

Atomic weight of C is 12u

Atomic weight of Br is 79u

Calculating molar mass of $2H_3NCH_3Br$ =2(1 x3+ 14+12+ 1 x 3 +79) = 111u

Hence, the molar mass of methylammonium bromide is 111u.

Learn more about molar mass here:

brainly.com/question/12127540

#SPJ1

8 0

2 years ago

How do i write a report about Gold mining?

pentagon [3]

Your Essay Must include:
Introduction:Brings the main idea,Must be atleast 3 sentences.
Body/Details:Supports the main Idea,Must be atleast 8 sentences.
Body/Details(Optional):Supports the main Idea,Must be atleast 8 sentences.
Conclusion:Tells a little more information.

4 0

3 years ago

A solute is a strong electrolyte that ionizes into 2 ions. What is the molar mass of this solute if 30.76 grams added to exactly

Whitepunk [10]

Answer:

34.9 g/mol is the molar mass for this solute

Explanation:

Formula for boiling point elevation: ΔT = Kb . m . i

ΔT = Temperatures 's difference between pure solvent and solution → 0.899°C

Kb = Ebullioscopic constant → 0.511°C/m

m = molality (moles of solute/1kg of solvent)

i = 2 → The solute is a strong electrolyte that ionizes into 2 ions

For example: AB ⇒ A⁺ + B⁻

Let's replace → 0.899°C = 0.511 °C/m . m . 2

0.899°C / 0.511 m/°C . 2 = m → 0.879 molal

This moles corresponds to 1 kg of solvent. Let's determine the molar mass

Molar mass (g/mol) → 30.76 g / 0.879 mol = 34.9 g/mol

4 0

3 years ago

5. Which are physical properties of a property of Aluminum metal?

4vir4ik [10]

Answer:

Aluminum is a shiny, silvery white colored metal that is light in weight and strong. Th density of aluminum is 2.7 g/mL, which means the metal will sink in water, but is still relatively light

Hope this helps (:

Mark me brainliest if its good for you :D take care.

8 0

3 years ago