The better we measure the better things ___

The ka of hf is 6.8 x 10-4. what is the ph of a 0.35 m solution of hf?

damaskus [11]

When the reaction equation is:

HF ↔ H+ + F-

and when the Ka expression
= concentration of products/concentration of reactions

so, Ka = [H+][F-]/[HF]

when we assume:

[H+] = [F-] = X

and [HF] = 0.35 - X

So, by substitution:

6.8 x 10^-4 = X^2 / (0.35 - X) by solving for X

∴ X = 0.015 M

∴[H+] = X = 0.015

when PH = -㏒[H+]

∴PH = -㏒0.015

= 1.8

6 0

3 years ago

I wrote that all matter consists of tiny particles called atoms. I also thought all atoms of a specific

Westkost [7]

Answer:

John Dalton

Explanation:

John Dalton in 1808 suggested that all matter consists of tiny particles called atoms and that the atoms of a specific element are identical.

He postulated the Dalton's atomic theory which has the following important parts;

All matters consists of indivisible particles called atoms
Atoms of the same element are similar and are different from atoms of other elements.
Atoms can neither be created nor destroyed.
Atoms combine in simple whole ratios to form compounds.

7 0

3 years ago

How are ionic bonds formed

Semenov [28]

Ionic bonds are formed when a cation and an anion transfer electrons. The anion gains electrons from the cation to finish its shell, and is usually a nonmetal or a metalloid. A cation gives the anion its electrons to get rid of its partial shell. Cations are metals.

7 0

3 years ago

Read 2 more answers

Object A specific heat is 2.45 J/g C and object B specific heat is 0.82 J/g C. Which object will heat up more if they have the s

Artist 52 [7]

Answer: Object B will heat up more.

Explanation:

The formula for specific heat is as follows.

Q = $m C \Delta T$

Where,

Q = heat provided

m = mass

C = specific heat

$\Delta T$ = change in temperature

Now, both the objects have same mass and equal amount of heat is applied.

According to the formula, the equation will be as follows.

$Q_{1}$ = $Q_{2}$

$m C_{1}\Delta T$ = $m C_{2}\Delta T_{2}$

Cancel m from both sides, as mass is same. Therefore,

$C_{1} (T_{f} - T_{i})_A$ = $C_{2}(T_{f} - T_{i})_B$

Cancel out the initial temperature and put the values of specific heat, then the equation will be as follows.

$2.45 (T_{f})_A$ = $0.82(T_{f})_B$

Therefore, from the above equation it can be concluded that the object with low specific heat will heat up more as its specific heat will be inversely proportional to its final temperature.

Hence, object B will heat up more.

4 0

3 years ago

A gas has a pressure of 810 kPa at 227°C. What will its pressure be at 27°C?

NeX [460]

486 kPa will be the pressure of gas at 27 degrees.

Explanation:

Data given :

Initial pressure of the gas P1 = 810 kPa

initial temperature of the gas T1 = 227 degrees OR 500.15 K

final pressure of the gas =?

final temperature of the gas = 27 degrees OR 300.15 K