All categories

4 years ago

What is the SI unit for amount of a substance?

Chemistry

2 answers:

Paladinen [302]4 years ago

8 0

Answer:

The SI unit for the amount of a substance is mole.

Explanation:

SI unit stands for International System of units. It is the standard system of unit of measurements.

SI unit defines the amount of substance to be proportional to the number of entities present. It's unit for the amount of substance is mole. Also, the unit symbol for mole is mol.

Brut [27]4 years ago

6 0

Answer:

Mole

Explanation:

You might be interested in

Which of the following is a chemical change? A. a solution of salt water being diluted as water is added to it B. soil drying as

Kobotan [32]

A chemical change occurs when the identity of a substance is changed. Silver tarnishing is a chemical change because silver and sulfur react to form a new substance, silver sulfide. In the other examples, the substances have not changed their identity and only physical changes have occurred. the correct answer is D

7 0

3 years ago

Read 2 more answers

The longer the bond, the smaller the bond enthalpy. the longer the bond, the smaller the bond enthalpy. false true

Temka [501]

True

As the shorter the bond, the stronger it is hence more energy will be required to overcome this bond

5 0

3 years ago

Consider an electron with charge âˆ’eâˆ’e and mass mmm orbiting in a circle around a hydrogen nucleus (a single proton) with cha

PtichkaEL [24]

Answer:

Explanation:

The net force on electron is electrostatic force between electron and proton in the nucleus .

Fc = $\frac{1}{4\pi\epsilon} \times \frac{e\times e}{r^2}$

This provides the centripetal force for the circular path of electron around the nucleus .

Centripetal force required = $\frac{m\times v^2}{r}$

$\frac{m\times v^2}{r}=\frac{1}{4\pi\epsilon} \times \frac{e\times e}{r^2}$

$v^2=\frac{e^2}{4\pi \epsilon m r}$

$v=(\frac{e^2}{4\pi \epsilon m r})^{\frac{1}{2} }$

5 0

3 years ago

Consider the following unbalanced chemical equation. C5H12(l) + O2(g) → CO2(g) + H2O(l) If 21.9 grams of pentane (C5H12) are bur

Marina CMI [18]

Answer : The mass of water produced will be 32.78 grams.

Explanation : Given,

Mass of $C_5H_{12}$ = 21.9 g

Molar mass of $C_5H_{12}$ = 72.15 g/mole

Molar mass of $H_2O$ = 18 g/mole

First we have to calculate the moles of $C_5H_{12}$ .

$\text{Moles of }C_5H_{12}=\frac{\text{Mass of }C_5H_{12}}{\text{Molar mass of }C_5H_{12}}=\frac{21.9g}{72.15g/mole}=0.3035moles$

Now we have to calculate the moles of $H_2O$ .

The balanced chemical reaction will be,

$C_5H_{12}(l)+8O_2(g)\rightarrow 5CO_2(g)+6H_2O(l)$

From the balanced reaction we conclude that

As, 1 mole of $C_5H_{12}$ react to give 6 moles of $H_2O$

So, 0.3035 moles of $C_5H_{12}$ react to give $0.3035\times 6=1.821$ moles of $H_2O$

Now we have to calculate the mass of $H_2O$ .

$\text{Mass of }H_2O=\text{Moles of }H_2O\times \text{Molar mass of }H_2O$

$\text{Mass of }H_2O=(1.821mole)\times (18g/mole)=32.78g$

Therefore, the mass of water produced will be 32.78 grams.

3 0

3 years ago

A correct name for the following compound is:_________.a) 4-bromo-3,8-dimethylbicyclo[5.2.2]nonane b) 3,8-dimethyl-4-bromo-bicyc

mixer [17]

Answer:

e) 4-bromo-3,8-dimethylbicyclo[5.2.0]nonane

Explanation:

The missing image of the the compound we are to name is attached below.

Before we can name an organic compound; It is crucial we know the guiding rules in naming them.

1. Select the longest continuous carbon chain as the root hydrocarbon and name according to the number of carbon atoms it contains, adding appropriate suffix to indicate the principal substituent group.

2. Number the carbon atoms in the root hydrocarbon from the end which gives the lowest number to the substituents.

3. If the same substituent is present two or more times in a molecule; the number of this substituent is indicated by the prefix di -(2), tri - (3) , tetra - (4) etc attached to the substituent name.

4. If there is more than one type of substituent in the molecule ; the substituents are named according to the alphabetical order but where there are mixed substituents ; the inorganic are named first.

5. In selecting and numbering the longest continuous chain, the functional groups are given preference over substituents., i.e the functional group is given the smallest possible number.

In the light of the above guiding rules; we were able to name the given compound because the compound contains nine carbons in the ring form which result to root name nonane. The two methyl are on the third and eight carbon; bromine is on the fourth carbon ; there are two cyclic ring present in the compound where we have 5 carbons in one structure, another 2 carbons in the second structure and zero carbon in the bridge structure which eventually result to the correct name:

4-bromo-3,8-dimethylbicyclo[5.2.0]nonane

5 0

3 years ago