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2 years ago

How many carbon atoms are contained in 84.3 g of ethyne (c2h2)?

1 answer:

7 0

To arrive at an answer in units of carbon atoms, first we must cancel out the grams by diving 84.3g C2H2 by the molar mass of C2H2 (26.038g/mol). This molar mass is calculated by adding the masses of 2 carbon atoms (12.011g/mol) and 2 hydrogen atoms (1.008g/mol). This renders units of moles of ethyne. Next multiply by Avagadro's number (6.022x10^23 atoms/mol) to cancel the moles of ethyne and reach atoms of ethyne. Finally, because there are 2 carbon atoms in C2H2, multiply by 2 atoms Carbon/1 atom C2H2 to reach the final answer of 3.90x10^24 atoms of Carbon. This answer has been rounded to three significant figures because the lowest known value of significant figures throughout the calculations was three (84.3). The entire process is as follows: 84.3g C2H2 x (1 mol C2H2)/(26.038 g C2H2) x (6.022x10^23 atoms C2H2)/(1 mol C2H2) x (1 atoms C2H2)/(2 atom C) = 3.90x10^24 atoms C

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Sodium reacts with chlorine gas according to the following reaction: 2Na(s)+Cl2(g)→2NaCl(s) What volume of Cl2 gas, measured at

asambeis [7]

Answer:6.719Litres of Cl2 gas.

Explanation:According to eqn of rxn

2Na +Cl2=2NaCl

P=689torr=689/760=0.91atm

T=39°C+273=312K

according to stoichiometry of the reaction,1Moles of Cl2 gives 2moles of NaCl

But 28g of NaCl was given,we have to convert this to moles by using the relation, n=mass/MW

MW of NaCl=23+35.5=58.5g/mol

n=28g(mass given of NaCl)/58.5

n=0.479moles of NaCl

Going back to the reaction,

if 1moles of Cl2 produces 2moles of NaCl

x moles of Cl2 will give 0.479moles of NaCl.

x=0.479*1/2

x=0.239moles of Cl2.

To find the volume, we use ideal ggas eqn,PV=nRT

V=nRT/P

V=0.239*0.082*312/0.91

V=6.719Litres

6 0

1 year ago

Classify the reaction that makes a firefly glow in terms of energy input and output

user100 [1]

It glow, so light energy go out of the system, exotermic

4 0

2 years ago

Who helps recycle nutrients through an ecosystem? A. producers and decomposers B. producers and consumers C. consumers and decom

s2008m [1.1K]

D. Producers im sure of it hope im right

8 0

2 years ago

Read 2 more answers

NH4NO3, whose heat of solution is 25.7 kJ/mol, is one substance that can be used in cold pack. If the goal is to decrease the te

makvit [3.9K]

Answer:

There are necessaries 35,2g of NH₄NO₃ per 100,0g of water to decrease the temperature of the solution from 25,0°C to 5,0°C

Explanation:

To decrease the temperature of the solution there are necessaries:

4,184J/g°C×(5,0°C-25,0°C)×(100,0g+X) = -Y

8368J + 83,68J/gX = Y (1)

Where x are grams of NH₄NO₃ you need to add and Y is the energy that you need to decrease the heat.

Also, the energy Y will be:

Y = 25700J/mol× $\frac{1mol}{80,043g}$ X

Y = 321J/g X (2)

Replacing (2) in (1)

8368J + 83,68J/g X = 321J/g X

8363J = 237,32J/gX

X = 35,2g

Thus, there are necessaries 35,2g of NH₄NO₃ per 100,0g of water to decrease the temperature of the solution from 25,0°C to 5,0°C

I hope it helps!

6 0

2 years ago

Which of the following statements best describes the properties of aluminum-28?

Contact [7]

d. When aluminum-28 undergoes beta decay, silicon-28 is produced.

Explanation:

When the nuclei of aluminium-28 decays, it produces silicon- 28:

Aluminium ²⁸₁₃Al

Silicon 28 ²⁸₁₄Si

beta particle ⁰₋₁ $\beta$

²⁸₁₃Al → ²⁸₁₄Si + ⁰₋₁ $\beta$

This way, the mass and atomic number are conserved.

Conservation of mass number:

28 = 28 + 0, 28 = 28

13 = 14 -1 , 13 = 13

Learn more:

Balancing nuclear equations brainly.com/question/10094982

#learnwithBrainly

5 0

2 years ago