How does the rate of reaction proceed with time

Calculate the average atomic mass element X

Leto [7]

Answer:

39.02 amu

Explanation:

The average atomic mass of an element can be calculated as follows :

$X=\dfrac{9.67\times 38+78.68\times 39+11.34\times 40+0.31\times 41}{100}\\\\X=\dfrac{3902.29}{100}\\\\X=39.02\ amu$

So, the atomic mass of the element X is 39.02 amu.

5 0

3 years ago

A chemical reaction produces formaldehyde, with a chemical formula of CH2O. Carbon is in Group 4A, oxygen is in Group 6A, and hy

Dahasolnce [82]

This problem is providing a comparison on the atoms forming formaldehyde, CH₂O, in terms of the groups they are in, C in group 4A, O in group 6A and H in group 1A, and it is asking for a description about the bonds once they are bonded in a formal Lewis dot structure.

In such a way, the attached file shows the Lewis dot structure, in which we can find two bonds between the two hydrogen atoms and the carbon one, and also, a double bond between carbon and oxygen.

The aforementioned is explained by bearing to mind the concept of octet, which states that elements in groups 4A, 5A, 6A and 7A are able to complete 8 valence electrons after bonding.

Thus, since carbon is in group 4A we infer it needs 4 more electrons to complete the octet, and that is achieved due to the 4 bonds it is having with the two hydrogen atoms and double bond with the oxygen atom.

In addition, since oxygen is in group 6A, we infer it needs two more electrons to complete its octet, which is attained via the double bond it has with the carbon atom. For hydrogen, however, it can complete one bond at maximum, because it is in group 1A, which means it can complete two valence electrons after bonding.

Learn more:

4 0

3 years ago

Which forensic scientist is, in part, responsible for the very specific evidence collection guidelines that exist in an effort t

Agata [3.3K]

D.) Edmond Locard. He formulated the basic principle that there will be a transfer of material if one object touches another. This material may contaminate a specimen and make it useless as forensic evidence.

“A.) Leone Lattes” is incorrect. He developed a method for blood typing that relied on detection of the specific antibodies.

“B.) Mathieu Orfila” is incorrect. He worked to make chemical analysis a routine part of forensics.

“C.) Hsi Duan Yu” is incorrect. It is a 13th century Chinese book that many people consider to be the first known guide to forensic pathology.

5 0

3 years ago

The molar mass of carbon dioxide is 44.0 g/mol. How many moles of CO2 are present in a 58.4 gram sample of CO2

inessss [21]

Answer:

1.33 moles CO2

Explanation:

The number you are converting is 58.4 g CO2, so you start with this value. The conversion factor is 44.0 g/mol CO2. In order to cross out the grams, the grams must go on the bottom of the conversion factor.

1 mol CO2
58.4 g CO2 x -------------------------- = 1.33 moles CO2
44.0 grams

The answer has three sig figs.

3 0

2 years ago

A rock is believed to have been formed 1.25 billion years ago, as calculated by using potassium-40 dating. If the half-life of p

Leya [2.2K]

Answer:

The answer to the question is

50 % of the original amount of potassium 40 will be left after one half life or 1.25 billion years

Explanation:

To solve the question we note that the half life is the time for half of the quantity of substance that undergoes radioactive decay to disintegrate, thus

we have

half life of potassium 40 K₄₀ = 1.25 billion years

To support the believe tht the rock was formed 1.25 billion years ago we have

$N_{(t)} =N_{(0)} (\frac{1}{2}) ^{\frac{t}{t_{\frac{1}{2} } } }$

After 1.25 billion years we have

$N_{(t)} =N_{(0)} (\frac{1}{2}) ^{\frac{1.25billion}{1.25 billion} } } }$ = $N_{(t)} =N_{(0)} (\frac{1}{2}) ^{1 } } }$ =0.5 of $N_{(0)}$ will be left or 50 % of the original amount of potassium 40 will be left

4 0

4 years ago