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3 years ago

Which substance has a molar mass of 142 g?

Chemistry

2 answers:

Nata [24]3 years ago

8 0

Answer:

Molar mass of P₂O₅ = 141.948 g/mol which is approximately 142 g/mol.

Explanation:

Molar mass of AlCl₃

Molar mass = 26.982 + 35.5 × 3 = 133.32 g/mol

Molar mass of BaCl₂

Molar mass = 137.33 + 35.5 × 2 = 208.33 g/mol

Molar mass of MgCl₂

Molar mass = 24.305 + 35.5×2 = 95.305 g/mol

Molar mass of P₂O₅

Molar mass = 30.974×2 + 16× 5 = 141.948 g/mol

In-s [12.5K]3 years ago

6 0

Answer:

$P_2O_5$

Explanation:

Molecular formulas is the actual number of atoms of each element in the compound. Molecular mass is the sum of the mass of each element which is present in the molecular formula is multiplied by their subscript which appear in the molecular formula.

The formula is = $AlCl_3$

Mass from the formula = 1×Mass of Aluminum + Mass of Chlorine×3 = 1×27 + 35.5×3 = 133.5 g/mol

The formula is = $BaCl_2$

Mass from the formula = 1×Mass of Barium + Mass of Chlorine×2 = 1×137 + 35.5×2 = 208 g/mol

The formula is = $MgCl_2$

Mass from the formula = 1×Mass of Magnesium + Mass of Chlorine×2 = 1×24 + 35.5×2 = 95 g/mol

The formula is = $P_2O_5$

Mass from the formula = 2×Mass of Phosphorus + Mass of oxygen×5 = 2×31 + 16×5 = 142 g/mol

Hence, correct answer is:- $P_2O_5$

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leva [86]

Answer:

One nucleophilic center

Explanation;

Nucleophile:

Nucleophile is a substance which is nucleus loving in nature (Nucleo; Nucleus , phile; Loving). It is known as a specie which donates a lone pair of electrons to electrophile (electron loving) in a chemical reaction.

Thus, Nucleophile is the region of higher electron density in a molecule and attacks on the lower electron density region of another molecule. Also, the nucleophile can also contain a negative charge.

Number of Nucleophilic centers in Methanol:

The chemical structure of Methanol is attached below and it can be observed that the oxygen atom is containing two lone pair of electrons. Hence, the oxygen atom can act as a nucleophilic center. Therefore, there is only one nucleophilic center in methanol.

H₃C-OH + H₃C-Br → H₃C-O-CH₃ + HBr

In above reaction methanol is acting as a nucleophile and is attacking on electrophilic center (Carbon) of methyl bromide yielding dimethyl ether.

8 0

2 years ago

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Liquid hexane

maks197457 [2]

Answer: The mass of $H_2O$ produced is 2.52 g

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ ......(1)

For hexane:

Given mass of hexane = 1.72 g

Molar mass of hexane = 86.18 g/mol

Putting values in equation 1, we get:

$\text{Moles of hexane}=\frac{1.72g}{86.18g/mol}=0.020mol$

For oxygen gas:

Given mass of oxygen gas = 8.0 g

Molar mass of oxygen gas= 32 g/mol

Putting values in equation 1, we get:

$\text{Moles of water}=\frac{8.0g}{32g/mol}=0.25mol$

The chemical equation for the combustion of hexane follows:

$2C_6H_{14}+19O_2\rightarrow 12CO_2+14H_2O$

By stoichiometry of the reaction:

If 2 moles of hexane reacts with 19 moles of oxygen gas

So, 0.020 moles of hexane will react with = $\frac{19}{2}\times 0.020=0.19mol$ of oxygen gas

As the given amount of oxygen gas is more than the required amount. Thus, it is present in excess and is considered as an excess reagent.

Thus, hexane is considered a limiting reagent because it limits the formation of the product.

By the stoichiometry of the reaction:

If 2 moles of hexane produces 14 moles of $H_2O$

So, 0.020 moles of hexane will produce = $\frac{14}{2}\times 0.020=0.14mol$ of $H_2O$

We know, molar mass of $H_2O$ = 18 g/mol

Putting values in above equation, we get:

$\text{Mass of }H_2O=(0.14mol\times 18g/mol)=2.52g$

Hence, the mass of $H_2O$ produced is 2.52 g

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3 years ago

Blance: Mg + HNO2 → Mg(NO2)2 + H2

Salsk061 [2.6K]

Explanation:

Mg + 2HNO2 → Mg(NO2)2 + H2

8 0

2 years ago

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The temperature at which a solid turns into a liquid is the _____ point.

NNADVOKAT [17]

A. melting

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2 years ago

In Rutherford's gold foil experiment, most alpha particles passed through the gold foil without deflection and were detected on

Gwar [14]

Answer:

Option D.

Explanation:

Some of the alpha particles Rutherford shot at the gold foil bounced back, some scattered; but the majority of them went right through. That meant there had to be some sort of positively charged subatomic particle in there that pulled them through, but it had to be at the center and couldn't take up a lot of room.

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