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3 years ago

If a DNA molecule is found to be made of 40% thymine,What percentage guanine would you expect

1 answer:

7 0

2 types of base pairs in DNA:
G-C 
A-T 
Since 40% is T, an equal amount will be A (40%+40%=80%)
20% is left, and this must also be equal, so G is 10% (C is the other 10%)

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The molar mass of glucose is 180.2 g/mol. How many grams of glucose will be produced when 132.0 g of CO2 reacts with an excess o

andriy [413]

Answer:

The mass in grams of glucose produced when 132.0 g of CO2 reacts with an excess of water is 90.1 grams

Explanation:

The chemical equation for the reaction is

6H₂O + 6CO₂ → C₆H₁₂O₆ + 6O₂

From the reaction, it is seen that 6 moles of H₂O reacts ith 6 moles of CO₂ to produce 1 mole of glucose C₆H₁₂O₆ and 6 moles oxygen gas

The molar mass of CO₂ = 44.01 g/mol

There fpre 132.0 g contains 132.0/44.01 moles or ≅ 3 moles

However since 6 moles of CO₂ produces 1 mole of O₂, then 3 moles of CO₂ will prduce 1/6×3 or 0.5 moles of C₆H₁₂O₆

and since the molar mass (or the mass of one mole) of C₆H₁₂O₆ is 180.2 grams/mole then 0.5 mole of C₆H₁₂O₆ will have a mass of

mass of 1 mole C₆H₁₂O₆ = 180.2 g

mass of 0.5 mole C₆H₁₂O₆ = 180.2 g × 0.5 = 90.1 grams

Mass of glucose produced = 90.1 grams

7 0

3 years ago

Which of the following statements is TRUE? (A) An ionic bond is much stronger than most covalent bonds.(B) Once dissolved in wat

Ainat [17]

Answer:

A) An ionic bond is much stronger than most covalent bonds.

Explanation:

D) Ionic compounds have high melting points causing them to be solid at room temperature, and conduct electricity when dissolved in water. Covalent compounds have low melting points and many are liquids or gases at room temperature.

C) An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed between a cation, which is usually a metal, and an anion, which is usually a nonmetal. A covalent bond involves a pair of electrons being shared between atoms.

A) Covalent bonds are stronger if you compare with ionic molecules, because their molecular orbital overlap is bigger. However, ionic molecules form lattices, thus the energy to break this lattice bond is stronger hence the ionic bond is stronger.

4 0

3 years ago

Many monatomic ions are found in seawater, including the ions formed from the following list of elements. Write the Lewis symbol

77julia77 [94]

Answer:

The Lewis structures are in image attached.

Explanation:

Lewis symbol is a representation of an element symbol along with its valence electrons around it in the form of dot(s).

Mono-atomic ions formed from the following :

(a) Cl

Chlorine's atomic number is 17 in which only 7 electrons are present in its valence shell .So in order to gain noble gas stability it will gain 1 electron to completes its octet

$Cl=1s^22s^22p^63s^23p^5$

$Cl^-=1s^22s^22p^63s^23p^6$

(b) Na

Sodium's atomic number is 11 in which only 1 electrons are present in its valence shell .So in order to gain noble gas stability it will loose 1 electron to completes its octet. In the Lewis symbol no dot shown as sodium has lost its 1 electron.

$Na=1s^22s^23p^63s^1$

$Na^+=1s^22s^23p^63s^0$

(c) Mg

Magnesium's atomic number is 12 in which only 2 electrons are present in its valence shell .So, in order to gain noble gas stability it will loose 2 electrons to completes its octet.

In the Lewis symbol no dot shown as magnesium has lost its 2 electrons.

$Mg=1s^22s^23p^63s^2$

$Mg^{2+}=1s^22s^23p^63s^0$

(d)Ca

Calcium's atomic number is 20 in which only 2 electrons are present in its valence shell .So, in order to gain noble gas stability it will loose 2 electron to completes its octet.

In the Lewis symbol no dot shown as calcium has lost its 2 electron.

$Ca= 1s^22s^22p^63s^23p^64s^2$

$Ca^{2+}=1s^22s^23p^6^23p^64s^0$

(e) K

Potassium's atomic number is 19 in which only 1 electrons are present in its valence shell .So, in order to gain noble gas stability it will loose 1 electron to completes its octet.

In the Lewis symbol no dot shown as calcium has lost its 1 electron.

$K= 1s^22s^22p^63s^23p^64s^1$

$K^{+}=1s^22s^23p^6^23p^64s^0$

(f) Br

Bromine's atomic number is 35 in which only 7 electrons are present in its valence shell .So in order to gain noble gas stability it will gain 1 electron to completes its octet

$Br=1s^22s^22p^63s^23p^63d^{10}4s^24p^5$

$Br^-= 1s^22s^22p^63s^23p^63d^{10}4s^24p^6$

(g) Sr

Strontium's atomic number is 38 in which only 2 electrons are present in its valence shell .So, in order to gain noble gas stability it will loose 2 electron to completes its octet.

In the Lewis symbol no dot shown as calcium has lost its 2 electron.

$Sr=1s^22s^22p^63s^23p^63d^{10}4s^24p^65s^2$

$Sr^{2+}=1s^22s^22p^63s^23p^63d^{10}4s^24p^65s^0$

(h) F

Florine's atomic number is 7 in which only 7 electrons are present in its valence shell .So in order to gain noble gas stability it will gain 1 electron to completes its octet.

$F=1s^22s^22p^5$

$F^-=1s^22s^22p^6$

5 0

2 years ago

stearic acid and linoleic acid stearic acid and linoleic acid stearic acid has the higher melting point, because it has two more

elena55 [62]

Acid palmitic acid has higher melting point, because it has two more methylene groups.

$\text { Myristic acid } \rightarrow \mathrm{CH}_3\left(\mathrm{CH}_2\right)_{12} \mathrm{COOH} \\& \text { Palmitic acid } \rightarrow \mathrm{CH}_3\left(\mathrm{CH}_2\right)_{14} \mathrm{COOH} \\$

Acid palmitic acid has higher melting point, because it has two more methylene groups.

Giving it a greater surface area and therefore more intermolecular van der waals interact than the myristic acid.

stearic arid $\mathrm{CH}_3\left(\mathrm{CH}_2\right)_{16} \mathrm{COOH}$

linoleic acid $\mathrm{C}_{18} \mathrm{H}_{32} \mathrm{O}_2$ (two double bond)

Stearic acid has higher Melting point, because it does not have any Carbon-Carbon double bonds, whereas linoleic acid has two cis double bonds which prevent the molecules from packing closely together.

Oleic Acid and Linoleic acid.

$\mathrm{C}_{18} \mathrm{H}_{34} \mathrm{O}_2$ -one double bond (cis)

Acid palmitic acid has higher melting point, because it has two more methylene groups.

For more such question on methylene group.

brainly.com/question/4279223

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4 0

7 months ago

Sodium carbonate, Na2CO3(s), can be prepared by heating sodium bicarbonate, NaHCO3(s). 2 NaHCO3(s) Na2CO3(s) + CO2(g) + H2O(g) K

Elenna [48]

Answer:

The pressure of CO2 = 0.48 atm

Explanation:

Step 1: Data given

Kp = 0.23

Step 2: The balanced equation

2NaHCO3(s) ↔ Na2CO3(s) + CO2(g) + H2O(g)

Step 3: Calculate the pressure of CO2

Kp = (p(CO2))*(p(H2O))

For 1 mol CO2 we have 1 mol H2O

x = p(CO2) = p(H2O)

Kp = 0.23 = x*x

x = √0.23

x = 0.48

pCO2 = x atm = 0.48 atm

The pressure of CO2 = 0.48 atm

5 0

2 years ago