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3 years ago

What is the total number of elements in group 17 that are gases at room temperature and standard pressure?

Chemistry

1 answer:

White raven [17]3 years ago

4 0

Answer:

Only to elements are gases at room temperature and standard pressure.

Fluorine and chlorine.

Explanation:

The group 17 is called halogen.

There are five elements in halogen group.

All halogens required one electrons to complete the octet and to get the noble gas electronic configuration.

All halogen elements have seven valance electrons.

Halogen elements:

Fluorine, chlorine, Bromine, iodine and astatine

Fluorine is gas at room temperature which s 25°C and standard pressure which is 1 atm.

It is present in the from of F₂.

Chlorine is also gas at room temperature and standard pressure.

It is present in the from of Cl₂.

The bromine is liquid under these condition.

Iodine and astatine are solids.

As we move down the group their melting and boiling points increases.

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Indicate which solution in each pair has the lower pH. Your response should be a four letter "word". The first letter should be

JulijaS [17]

Answer:

bcfh

Explanation:

HClO₄ reacts with water thus:

HClO₄ + H₂O → H₃O⁺ + ClO₄⁻

That means HClO₄ produce H₃O⁺ that decreases pH. That means the higher concentration of HClO₄ decreases pH. Thus, lower pH will be:

b) 0.2 M HClO4

The reaction of NaClO₄ is:

NaClO₄ + H₂O → OH⁻ + HClO₄ + Na⁺

The higher concentration of NaClO₄ the higher production of OH⁻ that increase pH, that means the lower concentration of NaClO₄ the lower pH, thus, the answer is:

<em>c) 0.1 M NaClO or</em>

HF reacts with water thus;

HF ⇄ H⁺ + F⁻

The equilibrium constant is:

k = [H⁺] [F⁻] / [HF] = 3,5x10⁻⁴

For HNO₂ equilibrium is:

HNO₂ ⇄ H⁺ + NO₂⁻

k = [H⁺] [NO₂⁻] / [HNO₂] = 4,5x10⁻⁴

As k value is higher for HNO₂, the concentration of H⁺ will be higher in this system doing the HNO₂ with the lower pH.

f) 0.1 M HNO2

NaOH is a strong base that produce OH⁻ that increase pH, pure water is neutral, thus, the lowe pH is:

h) pure water

I hope it helps!

7 0

3 years ago

Activation energy in reaction is used to:

vekshin1

Answer:

D — All of them

Explanation:

The activation energy in a reaction is the minimum amount of energy required for a chemical reaction to take place. Since all the options are processes in a chemical reaction, D should be the answer.

4 0

2 years ago

Read 2 more answers

Consider the reaction of ruthenium(III) iodide with carbon dioxide and silver. RuI3 (s) 5CO (g) 3Ag (s) Ru(CO)5 (s) 3AgI (s) Det

mixer [17]

Answer:

71.6 g of Ru(CO)₅ is the maximum mass that can be formed.

The limiting reactant is Ag

Explanation:

The reaction is:

RuI₃ (s) + 5CO (g) + 3Ag (s) → Ru(CO)₅ (s) + 3AgI (s)

Firstly we determine the moles of each reactant:

169 g . 1mol /481.77g = 0.351 moles of RuI₃

58g . 1mol /28g = 2.07 moles of CO

96.2g . 1mol/ 107.87g = 0.892 moles

Certainly, the excess reactant is CO, therefore, the limiting would be Ag or RuI₃.

3 moles of Ag react to 1 mol of RuI₃

Then 0.892 moles of Ag may react to (0.892 . 1) /3 = 0.297 moles

We have 0.351 moles of iodide and we need 0.297 moles, so this is an excess. In conclussion, Silver (Ag) is the limiting.

1 mol of RuI₃ react to 3 moles of Ag

Then, 0.351 moles of RuI₃ may react to (0.351 . 3) /1 = 1.053 moles

It's ok, because we do not have enough Ag. We only have 0.892 moles and we need 1.053.

5 moles of CO react to 3 moles of Ag

Then, 2.07 moles of CO may react to (2.07 . 3) /5 = 1.242 moles of Ag.

This calculate confirms the theory.

Now, we determine the maximum mass of Ru(CO)₅

3 moles of of Ag can produce 1 mol of Ru(CO)₅

Then 0.892 moles may produce (0.892 . 1) /3 = 0.297 moles

We convert moles to mass → 0.297 mol . 241.07g /mol = 71.6 g

8 0

3 years ago

What volume does 14 mol of gas occupy at STP? Round to the nearest hundredth.

Anna007 [38]

Answer:

The volume is 310 L

Explanation:

We use the ideal gas formula, with the constant R = 0.082 l atm / K mol. The STP conditions are 1 atm pressure and 273 K temperature. Solve for the formula, V (volume):

PV= nRT ---> V= (nRT)/P

V=( 14 mol x 0,082 l atm /K mol x 273 K)/ 1 atm

4 0

3 years ago

Which type of river is similar to a mature river, but flows more slowly so has less power to change the landscape? Select one: a

Ede4ka [16]

Answer:

The correct option is;

C. Old Age River

Explanation:

Among the three stages of the development of a river, which are the youthful, mature, and old age stages, the old age river is least dynamic

The water is very slow moving with a low gradient and lesser erosive power to alter the landscape which results in the appearance of flood planes

Examples of old age rivers include, lower Ganges, lower Nile, Indus, and Yellow rivers

Old age rivers are characterized by a broad shape, with a wide flood plane, a very gentle gradient and the water current is low.

5 0

3 years ago