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2 years ago

What type of bond holds the complementary bases together?.

Chemistry

1 answer:

olga55 [171]2 years ago

3 0

Answer:

hydrogen bonding

Explanation:

The two strands of DNA are held together by hydrogen bonds between complimentary nucleotides.

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A 1 liter solution contains 0.247 M nitrous acid and 0.329 M sodium nitrite. Addition of 0.271 moles of calcium hydroxide will:

Inessa05 [86]

Answer:

a. Raise the pH slightly

Explanation:

We know that

Pka of HNO2/KNO2 =3.39

Moles of HNO2 in the buffer=0.247 mol/L×1L=0.247 moles

Moles of NO2-=0.329mol/L×1L=0.329 moles

If 0.271 moles of Ca(OH)2 is added it will neutralise 0.136 moles of acid ,HNO2,remaining HNO2=0.247-0.136=0.111 moles

Moles of NO2- will increase as 0.0333 moles Ca(NO)2 will be formed =0.0333+0.036=0.0693 moles

pH=pka+log [base]/[acid] {henderson -hasselbach equation}

=3.39+log (0.0693/0.0317)=3.39+0.34=3.73

pH=3.73

4 0

3 years ago

You are planting flowers in large pots. You plan to plant flowers in 10 pots. 15 cups of potting soil will fill one pot. A bag o

dimaraw [331]

Answer:

I will need six (6) bags of potting soil

Explanation:

Since you plan on planting in 10 pots and need 15 cups of potting soil per pot, the total amount of potting soil you need (in cups) is 10 X 15 = 150 cups of potting soil.

We have that a bag contains 25 sups. to get the number of bags needed, we have to divide 150 by 25. This will give us 150 / 25 = 6 bags.

Therefore, I will need six (6) bags of potting soil

3 0

3 years ago

The sample of 15.0 g of KCl is dissolved into a solution with a total volume of 250.0 mL. What is the molarity of KCl in the sol

lina2011 [118]

Answer:

0.805 M.

Explanation:

Hello!

In this case, since the molarity of a solution is computing by dividing the moles of solute over the volume of solution in liters (M=n/V), for 15.0 g of potassium chloride (74.55 g/mol) we compute the corresponding moles:

$n=15.0gKCl*\frac{1molKCl}{74.55gKCl}=0.201molKCl$

Next, since the volume is 0.2500 in liters, the molarity turns out:

$M=\frac{0.201mol}{0.2500L} \\\\M=0.805M$

Best regards!

3 0

3 years ago

Is baking cake a acid base reaction

Zinaida [17]

When baking powder is added to a cake, the acid base reaction it undergoes with the acidic butter produces the carbon dioxide that makes the cake rise.

6 0

2 years ago

Calculate the freezing point of a solution containing 5.0 grams of KCl and 550.0 grams of water. The molal-freezing-point-depres

yulyashka [42]

Answer: The freezing point of solution is -0.454°C

Explanation:

Depression in freezing point is defined as the difference in the freezing point of pure solution and freezing point of solution.

The equation used to calculate depression in freezing point follows:

$\Delta T_f=\text{Freezing point of pure solution}-\text{Freezing point of solution}$

To calculate the depression in freezing point, we use the equation:

$\Delta T_f=iK_fm$

Or,

$\text{Freezing point of pure solution}-\text{Freezing point of solution}=i\times K_f\times \frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}$

where,

Freezing point of pure solution = 0°C

i = Vant hoff factor = 2

$K_f$ = molal freezing point elevation constant = 1.86°C/m

$m_{solute}$ = Given mass of solute (KCl) = 5.0 g

$M_{solute}$ = Molar mass of solute (KCl) = 74.55 g/mol

$W_{solvent}$ = Mass of solvent (water) = 550.0 g

Putting values in above equation, we get:

$0-\text{Freezing point of solution}=2\times 1.86^oC/m\times \frac{5\times 1000}{74.55g/mol\times 550}\\\\\text{Freezing point of solution}=-0.454^oC$

Hence, the freezing point of solution is -0.454°C

3 0

2 years ago