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3 years ago

65 POINTS AND BRAINLIEST PLEASE HELP ASAP

Chemistry

1 answer:

Naily [24]3 years ago

3 0

Answer:

Rosalind Elsie Franklin (25 July 1920 – 16 April 1958)was a British biophysicist and X-ray crystallographer who made critical contributions to the understanding of the fine molecular structures of DNA, RNA, viruses, coal and graphite. The DNA work achieved the most fame because DNA (deoxyribonucleic acid) plays essential roles in cell metabolism and genetics, and the discovery of its structure helped scientists understand how genetic information is passed from parents to children.

rosalindfranklin

Franklin is best known for her work on the X-ray diffraction images of DNA which led to discovery of DNA double helix. Her data, according to Francis Crick, was "the data we actually used" to formulate Crick and Watson's 1953 hypothesis regarding the structure of DNA.Franklin's X-ray diffraction image confirming the helical structure of DNA were shown to Watson without her approval or knowledge. Though this image and her accurate interpretation of the data provided valuable insight into the DNA structure, Franklin's scientific contributions to the discovery of the double helix are often overlooked. Unpublished drafts of her papers (written just as she was arranging to leave King's College London) show that she had independently determined the overall B-form of the DNA helix and the location of the phosphate groups on the outside of the structure. However, her work was published third, in the series of three DNA Nature articles, led by the paper of Watson and Crick which only hinted at her contribution to their hypothesis.

After finishing her portion of the DNA work, Franklin led pioneering work on the tobacco mosaic and polio viruses. She died in 1958 at the age of 37 from complications arising from ovarian cancer.

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MM H2O2 = 34.02 g/mol MM H2O = 18.02 g/mol MM O2 = 32 g/mol

Kaylis [27]

The grams of oxygen that are produced is 228.8 grams

calculation

2H₂O₂ → 2H₂O +O₂

Step 1: use the mole ratio to determine the moles of O₂

from equation above H₂O₂:O₂ is 2:1

therefore the moles of O₂ = 14.3 moles ×1/2 = 7.15 moles

Step 2: find mass of O₂

mass = moles × molar mass

= 7.15 moles × 32 g/mol =228.8 g

3 0

3 years ago

Which statement is correct?

sergiy2304 [10]

Answer:

a) is correct.......,.....

5 0

3 years ago

Calcium carbonate is often used as an antacid. Your stomach acid is composed of HCl at a pH of 1.5. If you ate toooo much Turkey

stiks02 [169]

Answer: 0.0237 g of calcium carbonate would be required to neutralize the given amount of HCl

Explanation:

pH is defined as the negative logarithm of hydrogen ion concentration present in the solution

$pH=-\log [H^+]$ .....(1)

Given value of pH = 1.5

Putting values in equation 1:

$1.5=-\log[H^+]$

$[H^+]=10^{(-1.5)}=0.0316M$

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

$\text{Molarity of solution}=\frac{\text{Number of moles of solute}\times 1000}{\text{Volume of solution (mL)}}$ .....(2)

We are given:

Volume of solution = 15.0 mL

Molarity of HCl = 0.0316 M

Putting values in equation 2:

$0.0316=\frac{\text{Moles of HCl}\times 1000}{15.0}\\\\\text{Moles of HCl}=\frac{0.0316\times 15.0}{1000}=4.74\times 10^{-4}mol$

The chemical equation for the reaction of HCl and calcium carbonate follows:

$2HCl+CaCO_3\rightarrow H_2CO_3+CaCl_2$

By the stoichiometry of the reaction:

2 moles of HCl reacts with 1 mole of calcium carbonate

So, $4.74\times 10^{-4}mol$ of HCl will react with = $\frac{1}{2}\times 4.74\times 10^{-4}=2.37\times 10^{-4}mol$ of calcium carbonate

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of calcium carbonate = $2.37\times 10^{-4}mol$

Molar mass of calcium carbonate = 100.01 g/mol

Putting values in the above equation:

$\text{Mass of }CaCO_3=(2.37\times 10^{-4}mol)\times 100.01g/mol\\\\\text{Mass of }CaCO_3=0.0237g$

Hence, 0.0237 g of calcium carbonate would be required to neutralize the given amount of HCl

7 0

3 years ago

C9H20 + 02 - > CO2 + H2O what is the balanced equation of this

san4es73 [151]

Hey there!

C₉H₂O + O₂ → CO₂ + H₂O

First let's balance the C.

There's 9 on the left and 1 on the right. So, let's add a coefficient of 9 in front of CO₂.

C₉H₂O + O₂ → 9CO₂ + H₂O

Next let's balance the H.

There's 2 on the left and 2 on the right. This means it's already balanced.

C₉H₂O + O₂ → 9CO₂ + H₂O

Lastly, let's balance the O.

There's 3 on the left and 19 on the right. So, let's add a coefficient of 9 in front of O₂.

C₉H₂O + 9O₂ → 9CO₂ + H₂O

This is our final balanced equation.

Hope this helps!

8 0

3 years ago

This is the equation for the combustion of propane.

yan [13]

Answer:

Explanation:

Reactants are the compounds which reaction produce the products. In general terms this can be expressed symbolically as follows:

reactants -> products

Other phenomena like heat are omitted because are not always present, that is, only compounds are included. Therefore, in this reaction the reactants are C3H8 (propane) and O2 ( oxygen) and the products are CO2 (carbon dioxide) and H2O (water)

8 0

3 years ago

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