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3 years ago

15

Which of the following is NOT true about one mole?

1 answer:

Lilit [14]3 years ago

7 0

The option in “the mass of 1me of carbon equals the mass of 1 mole of boron atoms” is false since

Mass=molesx molar mass

And the molar masses of these two elements are different so their masses aren’t equal

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DirectionsAnswer each question in the spaceQuestion1. Why does a neutral atom haveno overall charge?2. What determines the charg

mart [117]

1. An atom has an equel number of protons and electrons. Since protons are positive and electrons are negative, they are balanced out and there is no charge.

7 0

3 years ago

Which chemical is the reducing agent in the redox reaction below?

posledela

Option (a) is correct.

A reducing agent is the one which loses electrons to other substance.

Here, Zn has oxidation number 0 in the L.H.S of the equation, but on R.H.S its oxidation number is +2 i.e. it Zn has donated two of its electrons to $Fe^{2+}$ .

Hence, Zn is the reducing agent here.

6 0

3 years ago

The following information was recorded by a student team working to prepare nickel sulfate. Plan: Prepare NiSO4 by reacting NiO

mixas84 [53]

Answer:

The options e and d are correct.

Explanation:

Mass of NiO = 7.5 g

Moles of NiO = $\frac{7.5 g}{74.69 g/mol}=0.10 mol$

Moles of sulfuric acid = n

Volume of sulfuric acid ,V= 50 mL = 0.050 L

Molarity of sulfuric acid ,M = 6 mol/L

$n=M\time V=6mol/L\times 0.050 L =0.3 mol$

$NiO + H_2SO_4\rightarrow NiSO_4 + H_2O$

According to reaction, 1 mole of NiO reacts with 1 mole of sulfuric acid.

Then 0.10 moles of NiO reacts with :

$\frac{1}{1}\times 0.10 mol/=0.10 mol$ of sulfuric acid.

As we can see that sulfuric acid is in excess amount, so the amount of the product will depend upon amount of NiO.

According to reaction, 1 mole of NiO gives with 1 mole of $NiSO_4$ .

Then 0.10 moles of NiO wil give :

$\frac{1}{1}\times 0.10 mol/=0.10 mol$ of $NiSO_4$ .

Molar mass of $NiSO_4$ = 154.75 g/mol

Mass of 0.10 moles of $NiSO_4$ :

= 154.75 g/mol × 0.10 mol = 15.475 g

Theoretical mass of $NiSO_4$ = 15.475 g

Experimental yield of $NiSO_4$ = 17.4 g

Percentage yield :

$\Yield=\frac{\text{Experimental mass}}{\text{Theoretical mass}}\times 100$

Percentage yield of $NiSO_4$ :

$\Yield=\frac{17.4}{15.475 g}\times 100=112\%$

Moles of $NiSO_4.6H_2O$ = 262.85 g/mol × 0.10 mol = 26.285 g

Experimental yield of $NiSO_4.6H_2O$ = 17.4 g

Percentage yield of $NiSO_4.6H_2O$ :

$\Yield=\frac{17.4}{26.285 g}\times 100=66.2\%$

3 0

3 years ago

30.5 g of sodium metal reacts with chlorine gas to produce sodium chloride. How much (in grams) chlorine gas must react with thi

Lena [83]

Answer:

Mass of chlorine = 47.22 g

Explanation:

Given data:

Mass of sodium = 30.5 g

Mass of chlorine= ?

Solution:

Chemical equation:

2Na + Cl₂ → 2NaCl

Number of moles of Na:

Number of moles = mass/molar mass

Number of moles = 30.5g/ 23 g/mol

Number of moles = 1.33 mol

Now we will compare the moles of Cl ₂ with Na from balance chemical equation.

Na : Cl ₂

2 : 1

1.33 : 1/2×1.33 = 0.665 mol

Mass of chlorine gas:

Mass = number of moles × molar mass

Mass = 0.665 mol × 71 g/mol

Mass = 47.22 g

6 0

3 years ago

Match each pH value with the correct description. 7, 2, 8, 13, and 6 :)

bazaltina [42]

1.strong acid: 2
2.weak acid:6
3.strong base:13
4.weak base:8
5.neutral:7

8 0

3 years ago