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3 years ago

First correct answer will get brainliest

Chemistry

2 answers:

goblinko [34]3 years ago

7 0

Answer:

the second one

Explanation:

becuase i asked my teacher

amid [387]3 years ago

3 0

Answer:this ? 2end one

Explanation:

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0.5 gm of mixture of NH4Cl and NaCl was boiled with 25 ml of 0.95 N NaOH in a vessel till all the ammonia is expelled.The residu

GalinKa [24]

Answer:

72.66%

Explanation:

NH₄Cl reacts in presence of NaOH producing ammonia, NH₃, as follows:

NH₄Cl + NaOH → NaCl + NH₃ + H₂O

The residual NaOH reacts with H₂SO₄ as follows:

2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O.

The equivalent-gram of H₂SO₄ are:

16mL * 0.1N * 1.06 = 1.696mEq.

As the complete residual solution is 100mL but the neutralization was made only with 10mL, the mEq you need to neutralize the residual NaOH is:

1.696mEq * (100mL / 10mL) = 16.96mEq.

The mEq of NaOH you add in the first are:

25mL * 0.95mEq = 23.75mEq

That means the NaOH that reacts = moles of NH₄Cl is:

23.75mEq - 16.96mEq = 6.79mEq = 6.79mmoles NH₄Cl =

6.79x10⁻³ moles NH₄Cl

In grams (Using molar mass NH₄Cl = 53.5g/mol):

6.79x10⁻³ moles NH₄Cl * (53.5g / mol) =

0.3633g of NH₄Cl are in the original mixture.

% is:

0.3633g/ 0.5g * 100 = 72.66%

8 0

3 years ago

Zinc wire is added to an iron(II) nitrate solution.

Advocard [28]

Answer:

Zn(s) + Fe(NO₃)₂(aq) ⇒ Zn(NO₃)₂(aq) + Fe(s)

Explanation:

When metal zinc is added to an iron (II) nitrate solution, we can see the following redox reaction:

Zn(s) + Fe(NO₃)₂(aq) ⇒ Zn(NO₃)₂(aq) + Fe(s)

Zinc is oxidized since its oxidation number increases from 0 to +2.

Iron is reduced since its oxidation number decreases from +2 to 0.

3 0

3 years ago

A student weighed out a 2.055 g sample of a cobalt chloride hydrate, ConClmpH2O, where n, m, and p are integer values to be dete

topjm [15]

The given mass of cobalt chloride hydrate = 2.055 g

A sample of cobalt chloride hydrate was heated to drive off waters of hydration and the anhydrate was weighed.

The mass of anhydrous cobalt chloride = 1.121 g anhydrate.

The mass of water lost during heating = 2.055 g - 1.121 g = 0.934 g

Converting mass of water of hydration present in the hydrate to moles using molar mass:

Mass of water = 0.934 g

Molar mass of water = 18.0 g/mol

Moles of water = $0.934 g * \frac{1 molH_{2}O }{18 g H_{2}O } =0.0519 mol H_{2}O$

8 0

3 years ago

What is uranium made of? For a keynote (school)

never [62]

Pure uranium is radioactive. It will react with most nonmetallic elements to make compounds. When it comes into contact with air, a thin, black layer of uranium oxide will form on its surface. Uranium-235 is the only naturally occurring isotope that is fissile.

plz mark brainiest

7 0

3 years ago

Which statement supports the claim that the continental crust was once joined together as one supercontinent, Pangaea?

Liula [17]

Answer:

each continent shifts 2-5 inches per year so once it was joined then it is what it is now.In a million years again it will comes closer and wjo knows what will happen.moutains will be formed as the tectonic plates will collide.

5 0

3 years ago