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3 years ago

Please help me I need these answers

Chemistry

1 answer:

german3 years ago

6 0

Answer:

Q8) True

Q9) First ionization energy

Q10) Metal oxides

Explanation:

A common property of group one elements (alkali metals) is their combination with water to form basic solutions. E.g 2K(s)+2H2O(l)→2KOH(aq)+H2(g).

The distance of the outermost electron in the atom from the nucleus is inversely related to the first ionization energy. As the distance between the outermost electron and the nucleus in group 17 elements gets larger, the corresponding first ionization energies of elements in the group gets smaller.

Group 1 elements can combine with oxygen to give metal oxides. E.g 4K + O2 --> 2 K2O

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1. Starting with 9.3 moles of O 2 , how many moles of H 2 S will be needed and how many moles of SO 2 will

enyata [817]

Answer:

Moles of H₂S needed = 6.2 mol

Moles of SO₂ produced = 6.2 mol

Explanation:

Given data:

Number of moles of O₂ = 9.3 mol

Moles of H₂S needed = ?

Moles of SO₂ produced = ?

Solution:

Chemical equation:

2H₂S + 3O₂ → 2SO₂ + 2H₂O

Now we will compare the moles of oxygen with H₂S.

O₂ : H₂S

3 : 2

9.3 : 2/3×9.3 = 6.2 mol

Now we will compare the moles of SO₂ with both reactant.

O₂ : SO₂

3 : 2

9.3 : 2/3×9.3 = 6.2 mol

H₂S : SO₂

2 : 2

6.2 : 6.2 mol

So 6.2 moles of SO₂ are produced.

6 0

3 years ago

How many moles of zinc, Zn, are in 1.31×1024 Zn atoms?

liubo4ka [24]

Answer:

=7.89013× 10^47 moles of zinc

Explanation:

1 atom contains 6.023×10^23 moles.

1.31×10^24 atoms of zinc contain6.023×10^24×1.31×10^.24

6 0

2 years ago

I really need help, I don’t know what to do on this

Shtirlitz [24]

Answer:

A: dependent variable

B: experimental group

C: independent variable

D: control variables

E: control group

Explanation:

7 0

3 years ago

7. Suppose each of these isotopes emits a beta particle. Give the iso-

Volgvan

In a beta emission, the mass number of the daughter nucleus remains unchanged while the atomic number of the daughter nucleus increases by one unit. The following are isotopes produced when the following undergo beta emission;

1) potassium-42 ------> Ca - 42

2) iodine-131 ------------> Xe - 131

3) iron-52 ---------------> Co - 52

4) sodium-24 -----------> Mg -24

The daughter nucleus formed after beta emission is found one place after its parent in the periodic table.

Regarding the stability of the daughter nuclei, a nucleus is unstable if the neutron-proton ratio is less than 1 or greater than 1.5.

Hence, the following daughter nuclei are stable; Ca - 42, Xe - 131, Mg -24.

Learn more: brainly.com/question/1371390

7 0

3 years ago

A methanol-water mixture is to be flash distilled at 1 atm. If the feed is 25 mole %methanol, what are the liquid and vapor comp

frozen [14]

Answer:

Explanation:

Given that:

The distillation is carried out at a pressure of 1 atm

The feed harbors 25% mole of methanol (z)

The total moles of feed is usually 100 moles

In the system, we have both methanol and water

Using the total mole balance for the distillation column.

Fz = Lx + Vy

where;

F = amount of feed

z = mole fraction of ethanol (in feed)

L = amount of liquid product out of the column

V = amount of vapor product out of the column

x = mole fraction of methanol out of the liquid

y = mole fraction of methanol out of the vapor.

SO;

(a)

If all the feed is vaporized, then the vapor will likely have the same composition as the feed.

(b)

If no vaporization of the feed takes place, then the bottoms moving out of the column contains the same composition as the feed.

(c)

If 1/3 of the feed is vaporized; then 2/3 of the feed is at the bottom.

The balance equation would be:

$Fz = (\dfrac{2}{3}F) x + (\dfrac{1}{3}F)y \\ \\ z = \dfrac{2}{3}x+\dfrac{1}{3}y$

Replacing z = 0.25; we have:

$0.25 = \dfrac{2}{3}x+\dfrac{1}{3}y$

0.75 = 2x + y

(d)

If 2/3 of the feed is vaporized;

Then:

$Fz = (\dfrac{1}{3}F) x + (\dfrac{2}{3}F)y \\ \\ z = \dfrac{1}{3}x+\dfrac{2}{3}y$

replacing z = 0.25

$0.25 = \dfrac{1}{3}x+\dfrac{2}{3}y$

0.75 = x + 2y

6 0

2 years ago