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3 years ago

8

the relative molecular mass of sodium hydroxide is 40. if 60 grams of sodium hydroxide are dissolved in water how many moles wil

l there be in the solution?

1 answer:

goldfiish [28.3K]3 years ago

7 0

The formula to find the amount of moles of a substance used is: actual mass divided by relative molecular mass.

Therefore,
60/40 = 1.5 moles

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Arrange the following in order of increasing bond strength of the carbon oxygen bond:

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Answer:

The correct option is: Carbonate ion < Carbon dioxide < Carbon monoxide

Explanation:

Bond energy is defined as the average energy needed to break a chemical covalent bond and signifies the strength of chemical covalent bond.

The bond strength of a covalent bond depends upon the <u>bond length and the bond order.</u>

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Carbon dioxide (CO₂) has two carbon-oxygen (C-O) double bonds of equal length. Bond order 2.0

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Also, the bond length is <u>inversely proportional to the bond order and bond strength.</u>

Therefore, <u>order of C-O bond length:</u> Carbon monoxide<Carbon dioxide<Carbonate ion

<u>Order of C-O bond order</u>: Carbonate ion<Carbon dioxide<Carbon monoxide

<u>Order of C-O bond strength or energy</u><u>: Carbonate ion<Carbon dioxide<Carbon monoxide</u>

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Answer:

The elements in the alkaline earth metals group; beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra), have two electrons in their outer electronic shell.

Explanation:

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melisa1 [442]

Answer:

0.88 g

Explanation:

Using ideal gas equation to calculate the moles of chlorine gas produced as:-

$PV=nRT$

where,

P = pressure of the gas = 805 Torr

V = Volume of the gas = 235 mL = 0.235 L

T = Temperature of the gas = $25^oC=[25+273]K=298K$

R = Gas constant = $62.3637\text{torr}mol^{-1}K^{-1}$

n = number of moles of chlorine gas = ?

Putting values in above equation, we get:

$805torr\times 0.235L=n\times 62.3637\text{ torrHg }mol^{-1}K^{-1}\times 298K\\\\n=\frac{805\times 0.235}{62.3637\times 298}=0.01017\ mol$

According to the reaction:-

$MnO_2+4HCl\rightarrow MnCl_2+2H_2O+Cl_2$

1 mole of chlorine gas is produced when 1 mole of manganese dioxide undergoes reaction.

So,

0.01017 mole of chlorine gas is produced when 0.01017 mole of manganese dioxide undergoes reaction.

Moles of $MnO_2$ = 0.01017 moles

Molar mass of $MnO_2$ = 86.93685 g/mol

So,

$Mass=Moles\times Molar\ mass$

Applying values, we get that:-

$Mass=0.01017moles \times 86.93685\ g/mol=0.88\ g$

<u>0.88 g of $MnO_2(s)$ should be added to excess HCl (aq) to obtain 235 mL of $Cl_2(g)$ at 25 degrees C and 805 Torr.</u>

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Answer:

Protons

Explanation:

Protons are the subatomic particle that determines the identity of an element.

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