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2 years ago

How many hydrogen bonds are between cytosine and guanine

Chemistry

2 answers:

galina1969 [7]2 years ago

7 0

Answer:

3 hydrogen bonds

Explanation:

3 hydrogen bonds are between them

Dahasolnce [82]2 years ago

5 0

Answer:

Explanation:

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If 120.3 mL of water is shaken with oxygen gas at 2.1 atm, it will dissolve 0.0043 g O2. Estimate the Henry's law constant for t

nikklg [1K]

<u>Answer:</u> The Henry's law constant for oxygen gas in water is $1.702\times 10^{-5}g/mL.atm$

<u>Explanation:</u>

To calculate the molar solubility, we use the equation given by Henry's law, which is:

$C_{O_2}=K_H\times p_{O_2}$

where,

$K_H$ = Henry's constant = ?

$C_{O_2}$ = solubility of oxygen gas = $0.0043g/120.3mL$

$p_{O_2$ = partial pressure of oxygen gas = 2.1 atm

Putting values in above equation, we get:

$0.0043g/120.3mL=K_H\times 2.1atm\\\\K_H=\frac{0.0043g}{120.3mL\times 2.1atm}=1.702\times 10^{-5}g/mL.atm$

Hence, the Henry's law constant for oxygen gas in water is $1.702\times 10^{-5}g/mL.atm$

7 0

2 years ago

Cellulose could provide an abundant and cheap form of glucose for humans. Why is cellulose not a source of nutrients for humans?

mojhsa [17]

Answer:

Option (c).

Explanation:

Cellulose is one of the most important carbohydrate of the plant that provide structural framework to the plant cells. Cellulose is made of the monomer of the glucose that are linked through the beta glycosidic linkages.

Although cellulose contains large number of glucose but it cannot be used as the nutrient source for humans. Humans and other vertebrates lacks the enzyme cellulase that is required for the digestion of cellulose. Cellulose cannot be broken down in the human body.

Thus, the correct answer is option (c).

8 0

2 years ago

What is the mass, in pounds, of 389 mL of a gas that has a density of 1.29 g/L?

devlian [24]

Answer: Mass of gas is 0.001 pounds.

Explanation:

Density is defined as the mass contained per unit volume.

$Density=\frac{mass}{Volume}$

Given : Mass of gas = ?

Density of gas = $1.29g/L$

Volume of gas = 389 ml = 0.389 L (1L=1000ml)

Putting in the values we get:

$1.29g/L=\frac{mass}{0.389L}$

$mass=0.5grams$

$mass=0.5\times 0.002lb=0.001lb$ (1g =0.002 lb)

Thus the mass of gas is 0.001 pounds.

7 0

2 years ago

How many moles are in 7.2x10^15 atoms of Pb?

fiasKO [112]

<h3>Answer:</h3>

1.2 × 10⁻⁸ mol Pb

<h3>General Formulas and Concepts:</h3>

<u>Math</u>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right<u> </u>

<u>Chemistry</u>

<u>Atomic Structure</u>

Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

<u>Stoichiometry</u>

Using Dimensional Analysis

<h3>Explanation:</h3>

<u>Step 1: Define</u>

[Given] 7.2 × 10¹⁵ atoms Pb

<u>Step 2: Identify Conversions</u>

Avogadro's Number

<u>Step 3: Convert</u>

[DA] Set up: $\displaystyle 7.2 \cdot 10^{15} \ atoms \ Pb(\frac{1 \ mol \ Pb}{6.022 \cdot 10^{23} \ atoms \ Pb})$
[DA] Multiply/Divide [Cancel out units]: $\displaystyle 1.19562 \cdot 10^{-8} \ mol \ Pb$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 2 sig figs.</em>

1.19562 × 10⁻⁸ mol Pb ≈ 1.2 × 10⁻⁸ mol Pb

6 0

2 years ago

Research the Greenhouse effect and how it relates to heat transfer.

julsineya [31]

Answer:

The greenhouse effect is a phenomenon of radiative transfer, the process by which the energy of light waves is exchanged in matter. Radiative transfer dictates what energy is reflected, absorbed, and emitted. The greenhouse effect: A summary of the heat transfer in the Earth's atmosphere

Explanation:

trust me i have a huge brain and access to the internet

6 0

2 years ago