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3 years ago

Quick question.

1 answer:

5 0

Solution:- Halogens are fluorine, chlorine, bromine, iodine and Astatine(F, Cl, Br, I and At) and these are present in the 7A group of the periodic table. In modern periodic table this group is written as 17th group. This group elements have 7 valence electrons and so they are in group 7A.

So, the right choice is D. 7A.

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Cd(s)+2HCI(aq)---- H2(g)+CdCl2(aq). what volume in liters of 0.81m HCI solution would be needed to fully react with 32.71g Cd. a

BigorU [14]

Answer:

0.718L of 0.81M HCl are required

Explanation:

Based on the reaction:

Cd(s)+2HCI(aq) → H2(g)+CdCl2(aq)

1 mol of Cd reacts with 2 moles of HCl

To solve this question we must, as first, find the moles of Cd. With the moles of Cd we can find the moles of HCl needed to react completely with the Cd. With the moles and the molarity we can find the volume:

Moles Cd -Molar mass: 112.411g/mol-:

32.71g * (1mol / 112.411g) = 0.2910 moles Cd

Moles HCl:

0.2910 moles Cd * (2 moles HCl / 1mol Cd) =

0.5820 moles HCl

Volume:

0.5820 moles HCl * (1L / 0.81moles) =

<h3>0.718L of 0.81M HCl are required</h3>

6 0

3 years ago

The following image shows an owl swooping to grab a mouse.

Sloan [31]

Answer:

Predator-prey

Explanation:

Hope this helps.

4 0

2 years ago

Read 2 more answers

BONUS QUESTION

devlian [24]

Answer:

pH = 12.5

Explanation:

The reaction that takes place is

2OH⁻(aq) + Pb⁺²(aq) → Pb(OH)₂(s)

The OH⁻ species come from the metal hydroxide of the solution, and Pb(OH)₂ is the precipitate.

Now we convert 3.81 grams of Pb(OH)₂ into moles, using its molar mass:

3.81 g ÷ 241.12 g/mol = 0.0158 mol Pb(OH)₂

Now we convert 0.0158 Pb(OH)₂ moles into OH⁻ moles, using the stoichiometric coefficients of the reaction:

0.0158 mol Pb(OH)₂ * $\frac{2molOH^-}{1molPb(OH)_2}$ = 0.0316 mol OH⁻

With the given concentration (1 L), we calculate [OH⁻]:

[OH⁻] = 0.0316 mol / 1 L = 0.0316 M

Then we calculate the pOH of the solution:

pOH = - log[OH⁻] = 1.5

And finally we calculate the pH:

pH = 14 - pOH

pH = 12.5

6 0

2 years ago

How does rust serve as a preservative?

algol13

Answer:

see Explanation

Explanation:

it forms a layer over the metal and when removed the metal has been protected from other elements

6 0

3 years ago

Which is NOT a reason why we use the scientific method?

rusak2 [61]

Answer:

C. Because my teacher said so

Hope this helps :)

3 0

3 years ago

Read 2 more answers