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3 years ago

Why a common measuring system is important

Chemistry

1 answer:

Gekata [30.6K]3 years ago

6 0

So scientist around the world can share there info without having to convert and doing extra work.

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Measurements show that the enthalpy of a mixture of gaseous reactants increases by 319kJ during a certain chemical reaction, whi

hram777 [196]

Answer:

the change in energy of the gas mixture during the reaction is 227Kj

Explanation:

THIS IS THE COMPLETE QUESTION BELOW

Measurements show that the enthalpy of a mixture of gaseous reactants increases by 319kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that -92kJ of work is done on the mixture during the reaction. Calculate the change of energy of the gas mixture during the reaction in kJ.

From thermodynamics

ΔE= q + w

Where w= workdone on the system or by the system

q= heat added or remove

ΔE= change in the internal energy

q=+ 319kJ ( absorbed heat is + ve

w= -92kJ

If we substitute the given values,

ΔE= 319 + (-92)= 227 Kj

With the increase in enthalpy and there is absorbed heat, hence the reaction is an endothermic reaction.

8 0

3 years ago

Describe where a hydrogen bond can form among water molecules.

stiv31 [10]

Answer:

In water hydrogen bonding formed between partially negative oxygen and partially positive hydrogen atoms.

Explanation:

Hydrogen bond is a partially electrostatic attraction between hydrogen (H), which is bonded to a more electronegative atom such as nitrogen (N), oxygen (O) or fluorine (F), and another adjacent atom bearing a lone pair of electrons.

In water molecule hydrogen and oxygen have difference in electronegativity, due to which dipoles are form. One is partial positive on hydrogen atom and other is partial negative on oxygen atom. The electrostatic attraction occur between two oppositely charged poles which is known as hydrogen bonding.

4 0

3 years ago

Please help! 10 points!!

klemol [59]

Hi,
The answer is HF since hydrogen bonds are can be formed only between Hydrogen and Fluorine, Oxygen or Nitrogen.

8 0

3 years ago

Read 2 more answers

How many molecules are in 5.50 grams of AgNO3?

mixas84 [53]

Answer:

1.95*10²² molecules are in 5.50 grams of AgNO₃

Explanation:

Being the molar mass of the elements:

Ag: 107.87 g/mole
N: 14 g/mole
O: 16 g/mole

then the molar mass of the compound is:

AgNO₃: 107.87 g/mole + 14 g/mole + 3*16 g/mole= 169.87 g/mole

Then you can apply the following rule of three: if 169.87 grams of the compound are present in 1 mole, 5.50 grams will be present in how many moles?

$moles=\frac{5.50 grams*1 mole}{169.87 grams}$

moles= 0.0324

Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number applies to any substance.

You can apply the following rule of three: if by definition of Avogadro's Number 1 mole of the substance contains 6.023 * 10²³ molecules, 0.0324 moles how many molecules will it have?

$molecules=\frac{0.0324 moles*6.023*10^{23} molecules}{1 mole}$

molecules=1.95*10²²

<u><em>1.95*10²² molecules are in 5.50 grams of AgNO₃</em></u>

3 0

3 years ago

3. Description of which organelle betul "Creates a physical barrier ;

Ghella [55]

The cell membrane performs those functions. It is the outer layer of a cell and it creates a barrier, regulates material entry and exit, uses chemical signals, and creates structure.

4 0

2 years ago