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2 years ago

How much heat (in kilojoules) is evolved or absorbed in the reaction of 1.90 g of na with h2o? 2na(s) 2h2o(l)→2naoh(aq) h2(

Chemistry

1 answer:

myrzilka [38]2 years ago

3 0

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The temperature in a town started out at 55 degrees. By the end of the day the temperature dropped to -6 degrees.

garik1379 [7]

Answer:

The choice of the answer is fourth option that is -61 degrees.

Therefore the temperature drop is -61°Centigrade.

Explanation:

Given:

The temperature in a town started out at 55 degrees

Start temperature = 55°Centigrade. (Initial temperature)

End of the Day = -6°Centigrade. (Final temperature)

To Find:

How far did the temperature drop?

Solution:

We will have,

$\textrm{Temperature drop}=\textrm{Final temperature}-\textrm{Initial temperature}$

Substituting the above values in it we get

$\textrm{Temperature drop}=-6-55\\\\\therefore \textrm{Temperature drop}=-61\° centigrade$

Therefore the temperature drop is -61°Centigrade.

4 0

3 years ago

An unknown liquid is composed of 34.31% c, 5.28% h, and 60.41% i. The molecular weight is 210.06 amu. What is the molecular form

ozzi

In an unknown liquid, the percentage composition with respect to carbon, hydrogen and iodine is 34.31%, 5.28% and 60.41% respectively.

Let the mass of liquid be 100 g thus, mass of carbon, hydrogen and oxygen will be 34.31 g, 5.28 g and 60.41 g respectively.

To calculate molecular formula of compound, convert mass into number of moles as follows:

$n=\frac{m}{M}$

Molar mass of carbon, hydrogen and iodine is 12 g/mol, 1 g/mol and 126.90 g/mol.

Taking the ratio:

$C:H:I=n_{C}:n_{H}:n_{I}$

Putting the values,

$C:H:I=\frac{34.31 g}{12 g/mol}:\frac{5.28 g}{1 g/mol}:\frac{60.41 g}{126.90 g/mol}=6:11:1$

Thus, molecular formula of compound will be $C_{6}H_{11}I$ .

4 0

2 years ago

If the half life is 6.3 minutes how much of a 128.0 milligram sample will remain after 15 minutes

zaharov [31]

Answer:

24.5

Explanation:

15/6.3 => 2.38 half lives passed.

.5^2.38 => 0.19198 decimal representation of the percentage that is left over after 2.38 half lives have passed.

0.19198 *128 = 24.5 mg of the material remaining.

6 0

2 years ago

Which equation obeys the law of conservation of mass?

valina [46]

4Fe + 3O2 -> 2 (Fe2O3)

Both sides have 4Fe and 6O.

7 0

3 years ago

Read 2 more answers

Jennifer observes a weather map showing tomorrow's weather. She predicts that air will travel from the low pressure system to th

Paha777 [63]

Answer:

b The wind will travel from the high pressure system to the low pressure system.

Explanation:

I think this is the answer not sure.

7 0

2 years ago