If you have 74.4 liters Argon what is the mass in grams

What must be true for a substance to be able to dissolve in water?

JulsSmile [24]

B. i think not 100% sure

6 0

3 years ago

Which of the following buffer systems would you use if you wanted to prepare a solution having a pH of approximately 9.5?Which o

zalisa [80]

Answer:

b. 0,08M NH₄⁺ / 0,12M NH₃

Explanation:

The buffers are:

a. 0,08M H₂PO₄⁻ / 0,12M HPO₄²⁻

b. 0,08M NH₄⁺ / 0,12M NH₃

It is possible to find out the pH of a buffer using Henderson-Hasselbalch formula:

pH = pka + log₁₀ [A⁻] / [HA] (1)

Where A⁻ is the conjugate base of the weak acid, HA.

a. For the system H₂PO₄⁻ / HPO₄²⁻ pka is 7,198. Replacing in (1)

pH = 7,198 + log₁₀ [0,12] / [0,08]

pH = 7,37

That means this buffer system don't have a pH of approximately 9,5

b. For the system NH₄⁺ / NH₃ pka is 9,3. Replacing in (1)

pH = 9,3 + log₁₀ [0,12] / [0,08]

pH = 9,50

That means this buffer system is the buffer you need to use.

I hope it helps!

7 0

3 years ago

A galvanic^cell consists of left ompartmcnt with a tin elcctrode in contact with 0.1 M Sn(NO_3)_2(aq) and a right compartment wi

lana66690 [7]

Answer:

Electrons will flow from left to right through the wire.

Pb^2+ ions will be reduccd to Pb metal.

The concentration of Sn2+ ions in the left compartment will increase.

Explanation:

Looking at the relative electrode potentials of the two metals

Sn= -0.14

Pb=-0.13

Tin is expected to function as the anode (left hand half cell) and lead as the anode (right hand half cell) tin oxidizes to sn^2+ hence its concentration increases on the left compartment while lead is reduced to ordinary lead metal on the right hand half cell . since oxidation occurs on the left hand side, electrons flow from left to right.

6 0

3 years ago

Indicate the oxidation number of oxygen for each compound in the following reaction: 2H2O2(aq)→ 2H2O(l) O2(g) Select the choice

Aleksandr [31]

Answer:

2H2O2(aq)→ 2H2O(l) O2(g) : The oxidation number of oxygen for each compound is -1, -2, 0

Explanation:

In peroxides the oxidation state of oxygen is -1, since one oxygen bonds to the other oxygen and a hydrogen and the bound oxygen captures the electron of the remaining hydrogen. Through a scheme would be

H --- O --- O --- H

We remember that oxygen needs two electrons to get to have the configuration of the nearest noble gas (Lewis octet rule). In Peroxides, the oxygen is linked by covalent bonds. If we take it strictly, peroxide is a grouping of two oxygen, having the whole valence -2. which is why it is usually said that it is when oxygen has a valence -1

As we said the oxidation state is -2, the one that appears in the water molecule, since Hydrogen acts with valence +1 and it is 2 atoms that give up electrons to compensate for oxygen.

In the O2 it acts with valence 0 since we talk about gas in its elementary state. All diatomic molecules in their elemental state, generally gases or metals in solid state, act with a valence of 0.

3 0

3 years ago

Can someone please tell me this answer

ra1l [238]

Answer:

Carbon + oxygen

C + O2 - CO2

Sulphur + Oxygen

S + O2 - SO2

5 0

3 years ago