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2 years ago

The efficiency of a machine cannot be 100 percentageJustify this statment

Chemistry

1 answer:

andre [41]2 years ago

3 0

Answer:

A machine cannot be 100 percent efficient because output of a machine is always less than input. A certain amount of work done on a machine is lost to overcome friction and to lift some moving parts of the machine.

Explanation:

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HClO4 acid solution has a concentration of 5 Molarity. Calculate the concentration of this solution in

Nutka1998 [239]

Answer:

1. Percentage by weight = 0.5023 = 50.23 %

2. molar fraction =0.153

Explanation:

We know that

Molar mass of HClO4 = 100.46 g/mol

So the mass of 5 Moles= 5 x 100.46

Mass (m)= 5 x 100.46 = 502.3 g

Lets assume that aqueous solution of HClO4 and the density of solution is equal to density of water.

Given that concentration HClO4 is 5 M it means that it have 5 moles of HClO4 in 1000 ml.

We know that

Mass = density x volume

Mass of 1000 ml solution = 1 x 1000 =1000 ( density = 1 gm/ml)

m'=1000 g

Percentage by weight = 502.3 /1000

Percentage by weight = 0.5023 = 50.23 %

We know that

molar mass of water = 18 g/mol

mass of water in 1000 ml = 1000 - 502.3 g=497.9 g

So moles of water = 497.7 /18 mole

moles of water = 27.65 moles

So molar fraction = 5/(5+27.65)

molar fraction =0.153

6 0

2 years ago

How would the electron configuration of nitrogen change to make a stable configuration?

AnnZ [28]

The answers to the questions are as follows;

It would gain three electrons
The difference in their electronegativities.
The elements have filled Valence levels
potassium (K) with a 1+ charge
ClO-

Question 1:

How would the electron configuration of nitrogen change to make a stable configuration?

Since Nitrogen has 5 Valence electrons, it needs 3 electrons to attain it's octet configuration. As such, it gains 3 electrons.

Question 2:

Which quantity determines how two atoms bond.

The quantity which determines how two atoms bond is The difference in their electronegativities.

Question 3:

Which statement best explains why the elements in Group 18 do not have electronegativity values.

This is because the elements have filled Valence levels.

Question 4:

Based on patterns in the periodic table, which ion has a stable valence electron configuration

The ion which has a stable Valence electron configuration is potassium (K) with a 1+ charge

Question 5;

Which chemical formula represents a polyatomic ion?

The chemical formula which represents a polyatomic ion is; ClO-

5 0

2 years ago

Calculate the volume of carbon dioxide and water vapour produced and the volume of oxygen remaining, when 20.0 dm3 of propane re

laiz [17]

Answer:

80cm3 of water, and 60cm3 carbon IV oxide is formed while 20cm3 of oxygen is left unreacted.

Explanation:

From Gay-Lussac's law, there are five volumes of oxygen, 1 volume if propane, 4 volumes of water and three volumes of CO2. Applying this shows the reacting volumes as we have in the image attached, hence the volumes left after reaction.

6 0

2 years ago

Which of these statements is not true?question 20 options:atoms of isotopes of an element have different numbers of protons.atom

Greeley [361]

The first one is the answer
isotopes of an atom have different number of neutrons . the number of protons are not different in isotopes of an atom

4 0

2 years ago

Read 2 more answers

There are ________ σ bonds and ________ π bonds in h3c-ch2-ch=ch-ch2-c≡ch.

FrozenT [24]

The number of sigma and pi bonds are,

Sigma Bonds = 16

Pi Bonds = 3

Explanation:
Every first bond formed between two atoms is sigma. Pi bond is formed when already a sigma bond is there. While in case of Alkyne (triple Bond) there is one sigma and one pi bond already present, so the third bond is formed by second side-to-side overlap of orbitals, hence, a second pi bond is formed.
Below all black bonds are sigma bonds, while in alkene there is one pi bond and in alkyne there are two pi bonds.

6 0

2 years ago

The efficiency of a machine cannot be 100 percentageJustify this statment​

The efficiency of a machine cannot be 100 percentageJustify this statment