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3 years ago

1. How did Mosely contribute to the periodic table arrangement?

Chemistry

1 answer:

KIM [24]3 years ago

4 0

Answer:

1. Mosely arranged the elements based on the increasing number of protons, atomic number.

2. According to Moseley, similar properties recur periodically when elements are arranged according to increasing atomic number. Atomic numbers, not weights, determine the factor of chemical properties. Mendeleev ordered his elements in order of their relative atomic mass, and this gave him some problems.

Explanation:

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How much energy is needed to raise the temperature of 2g of water 5°C

Scilla [17]

Answer:this case, the mass is 2.0g, the specific heat capacity of water is 4.18J/g/K, and the change in temperature is 5.0°C=5K , therefore the energy needed to raise it is: 5×2×4.18=41.8J

Explanation:

3 0

10 months ago

2. Consider the reaction 2 Cg H18 (4) +250â (9) âº 16 co, (g) + 18 HâO(g) la How many moles of H20co) are produced, when |--16:1

Sladkaya [172]

Answer :

(a) The moles of water produced are 145.35 moles.

(b) The mass of oxygen needed are 3080.8 grams.

Solution for part (a) : Given,

Moles of $C_8H_{18}$ = 16.15 moles

First we have to calculate the moles of $H_2O$

The balanced chemical reaction is,

$2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O$

From the balanced reaction we conclude that

As, 2 moles of $C_8H_{18}$ react to give 18 moles of $H_2O$

So, 16.15 moles of $C_8H_{18}$ react to give $\frac{16.15}{2}\times 18=145.35$ moles of $H_2O$

The moles of water produced are 145.35 moles.

Solution for part (b) : Given,

Mass of $C_8H_{18}$ = 878 g

Molar mass of $C_8H_{18}$ = 114 g/mole

Molar mass of $O_2$ = 32 g/mole

First we have to calculate the moles of $C_8H_{18}$ .

$\text{ Moles of }C_8H_{18}=\frac{\text{ Mass of }C_8H_{18}}{\text{ Molar mass of }C_8H_{18}}=\frac{878g}{114g/mole}=7.702moles$

Now we have to calculate the moles of $O_2$

The balanced chemical reaction is,

$2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O$

From the balanced reaction we conclude that

As, 2 moles of $C_8H_{18}$ react with 25 moles of $O_2$

So, 7.702 moles of $C_8H_{18}$ react with $\frac{7.702}{2}\times 25=96.275$ moles of $O_2$

Now we have to calculate the mass of $O_2$ .

$\text{ Mass of }O_2=\text{ Moles of }O_2\times \text{ Molar mass of }O_2$

$\text{ Mass of }O_2=(96.275moles)\times (32g/mole)=3080.8g$

The mass of oxygen needed are 3080.8 grams.

6 0

2 years ago

Two litres of an ideal gas at a pressure of 10 atm expands isothermally into a vacuum until its total volume is 10 litres. How m

nlexa [21]

Answer:

The work done and heat absorbed are both -8,1 kJ

Explanation:

The work done in an isobaric process is defined as:

W = -P (Vf - Vi)

Where P is pressure ( 10 atm)

Vf = 10 L

Vi = 2 L

Thus, W = -80 atm×L ≡ -8,1 kJ

This is the work done in expansion of the gas. As the gas remains at the same temperature, there is no change in internal energy doing that all work was absorbed as heat.

I hope it helps!

4 0

2 years ago

How many neutrons are in an atom of tin? Round your answer to the nearest whole number.

Ray Of Light [21]

There are 50 neutrons in and atom of tin.

8 0

3 years ago

Read 2 more answers

David walks 10 Km North. He turns East and walks 10 more Km. What is his distance

BigorU [14]

Answer:

20 km

Explanation:

he walks 10 km + another 10 km so 20 :)

3 0

2 years ago