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3 years ago

Round off each number to the indicated number significant figures (sf):

Chemistry

1 answer:

qaws [65]3 years ago

7 0

Answer :

(a) The given number in 2 significant figures will be, $3.6\times 10^3$

(b) The given number in 4 significant figures will be, $3.583\times 10^1$

(c) The given number in 3 significant figures will be, $2.24\times 10^1$

Explanation :

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

(a) The given number 00003554 converted into 2 significant figures.

In 00003554, there are 4 significant figures. Now we have to convert it into 2 significant figures.

The given number in 2 significant figures will be, $3.6\times 10^3$

(b) The given number 35.8348 converted into 4 significant figures.

In 35.8348, there are 6 significant figures. Now we have to convert it into 4 significant figures.

The given number in 4 significant figures will be, $3.583\times 10^1$

(c) The given number 22.4555 converted into 3 significant figures.

In 22.4555, there are 6 significant figures. Now we have to convert it into 3 significant figures.

The given number in 3 significant figures will be, $2.24\times 10^1$

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How do the names of covalent compounds differ from the names of ionic compounds?

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Covalent bonds are named by using prefixes that give the number of atoms of each element in the compound. Ionic compounds are named by replacing the ending of the nonmetal with ate or ite. 6.

plz brain list me 5 star me thank me but thank you

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3 years ago

Convert 150 kPa to atmospheres. *

lakkis [162]

Answer: 1.48 atmosphere

Explanation:

Pressure in kilopascal = 150

Pressure in atmosphere = ?

Recall that 1 atmosphere = 101.325 kilopascal

Hence, 1 atm = 101.325 kPa

Z atm = 150 kPa

To get the value of Z, cross multiply

150 kPa x 1 atm = 101.325 kPa x Z

150 kPa•atm = 101.325 kPa•Z

Divide both sides by 101.325 kPa

150 kPa•atm/101.325 kPa = 101.325 kPa•Z/101.325 kPa

1.48 atm = Z

Thus, 150 kPa is equivalent to 1.48 atmospheres

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3 years ago

What is the difference between nuclear fusion and nuclear fission?

True [87]

Answer:

[Fusion: Nuclei Fuse together and release energy] [Fission: Pressure and energy is released. This release of energy, is what causes the unstable atom to split to an isotope. I hope this helps!]

[isotopes can split too. At least some.]

Explanation:

Imagine you are trying to push something heavy, fusion is how you can join together and help each other to push this heavy material.

Fun fact! Heavier materials have more inertia against other forces acting on them.

You push harder, harder and harder! Until its pushed.

This will release a lot of energy which escalates to an extended length.

It might not be the finest example, it helped me to understand the basics.

Fission. Imagine having so much energy, in this case, try thinking of so many people in a tight space. What do you do? You will eventually start to escape and leave the room. This is the act of splitting the atom.

This won't be the same than how it was before.

Again, Energy is released (energy!!).

For anyone struggling with this, although it might not be the best idea, I would recommend researching the more advaced options for this topic.

This will give you a wide range of information which can develop your current knowledge about, "Nuclear Fission and Fusion."

It will be difficult, it definitely was for me when I was a child (starting to study science).

Just keep trying, you'll get it.

4 0

3 years ago

Be sure to answer all parts. In winemaking, the sugars in grapes undergo fermentation by yeast to yield CH3CH2OH (ethanol) and C

Ede4ka [16]

Answer:

a)- Fermentation = - 2 816 kJ/mol

Respiration = - 1409.2 kJ/mol

b)C₂H₅OH (l) + 3O₂ (g) → 3H₂O(g) + 2CO₂(g)

c) combustion per mol of sugar

Explanation:

The fermentation of sugar is given as follows:

C₆H₁₂O₆ (s) + 6O₂ (g) → 6O₂ (g) + 6H₂O (l)

ΔHrxn = ΔHformation (products) - ΔHformation (reactants)

= (6 mol × -393.5kJ/mol)+ (6mol × -285.8kJ/mol) - (1 mol × -1260kJ/mol + 6mol × 0)

= -2 816 kJ/mol

The heat of combustion of ethanol is given as follows:

C₂H₅OH (l) + 3O₂ (g) → 3H₂O(g) + 2CO₂(g)

Let's assume that 1 mol of ethanol is burnt. The heat of reaction, ΔHrxn is given by this equation:

ΔHrxn = ΔHformation (products) - ΔHformation (reactants)

= (2 mol× - 393.5kJ/mol) + ( 3mol × -285.8kJ/mol) - [ (1mol × -235 kJ/mol) + ( 3mol × 0.0000kJ)]

= -1644 - (-235.2)

= - 1409.2 kJ/mol

Therefore, the combustion of ethanol is exothermic. In other words, heat iis given off (this is signified by the negative sign)

b) Ethanol, like any other fuel, burns up to give water and carbon dioxide. This is based on the assumption that the combustion is complete and no side reactions take place. The combustion of ethanol is given as follows:

C₂H₅OH (l) + 3O₂ (g) → 3H₂O(g) + 2CO₂(g)

The physical states are given in the parentheses.

c) From the comparisons of the ΔHrxn, sugar produces more energy.

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4 years ago

Consider the four phases of matter. How do the characteristics of a liquid differ from a solid?

Kitty [74]

A solid has a definite shape while a liquid does not. hope I helped!

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3 years ago