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3 years ago

A base has Kb of 2.5 x 10-11. which of the following statements is true?(1 point)

1 answer:

3 0

I disagree with the answer pick of D. If you have a neutral pH 7 solution and you proceed to add a base even with an relatively insignificantly low Kb your solution would still be more basic then acidic. The answer should be b which is true that the base only ionizes slightly in aqueous solution. This is also truer to the definition of what Kb represents.

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Can someone please help me with this, I’ll give Brainly!

Art [367]

Answer:

Explanation:

See attached table.

Note that:

1 mole = 6.02x10^23

Molar mass is grams/mole. For the elements, the atomic mass is the same number as molar mass, just expressed as grams/mole.

5 0

3 years ago

How many milliliters of 0.1 m hcl is required to react with 0.15g sodium carbonate (na2co3?

docker41 [41]

1) Write the balanced chemical equation

2HCl + Na2 CO3 ----------> 2NaCl + H2CO3

2) Write the molar ratios:

2 mol HCl : 1 mol Na2CO3 : 2 mol NaCl : 1 mol H2CO3

3) Convert 0.15g of sodium carbonate to number of moles

3a) Calculate the molar mass of Na2CO3

Na: 2 * 23 g/mol = 46 g/mol

C: 12 g/mol =

O: 3 * 16 g/mol = 48 g/mol

molar mass = 46g/mol + 12g/mol + 48g/mol = 106 g/mol

3b.- Calculate the number of moles of Na2CO3

# moles = grams / molar mass = 0.15 g / 106 g/mol = 0.0014 mol Na2CO3

4) Calculate the number of moles of HCl from the molar proportion:

[0.0014 mol Na2CO3] * [2 mol HCl / 1 mol Na2CO3] = 0.0028 mol HCl

5) Calculate the volume of HCl from the definition of Molarity

Molarity, M = # moles / volume in liters

=> Volume in liters = # moles / M = 0.0028 mol / 0.1 M = 0.028 liters

0.028 liters * 1000 ml / liter = 28 ml.

Answer: 28 mililiters of 0.1 M HCl.

7 0

3 years ago

the hemiacetal below is treated with 18o-labeled methanol (ch3o*h) and acid. where will the label appear in the products?

ioda

The 18o-labeled methanol (CH3O*H) will appear in the products side at position b.

<h3>Position of 18o-labeled methanol in the products</h3>

The 18O label will appear at position b in the product as indicated in the image.

This methoxy group in the product formed in position b comes from the 18O-labeled methanol (CH3OH).

While the oxygens at positions a and c in the product come from the unlabeled hemiacetal.

Thus, the 18o-labeled methanol (CH3O*H) will appear in the products side at position b.

Learn more about methanol here: brainly.com/question/17048792
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2 years ago

IM ON A TIMER! What are the main types of star clusters? Check all that apply.

jekas [21]

There are globular and open star clusters, but there are no binary, eclipsing, or wobbling ones.

8 0

3 years ago

Read 2 more answers

A drop of water with a mass of 0.48 g is vaporized at 100 ∘C and condenses on the surface of a 55- g block of aluminum that is i

bagirrra123 [75]

The final temperature in Celsius of the metal block is 49°C.

<h3>How to find the number of moles ?</h3>

Moles water = $\frac{\text{Given mass}}{\text{Molar Mass}}$

= $\frac{0.48\ g}{18\ \text{g/mol}}$

= 0.0266 moles

Heat lost by water = 0.0266 mol x 44.0 kJ/mol

= 1.17 kJ

= 1170 J [1 kJ = 1000 J]

Heat lost = Heat gained

Heat gained by aluminum = 1170 J

1170 = 55 x 0.903 (T - 25) = 49.7 T - 1242

1170 + 1242 = 49.7 T

T = 48.5°C (49°C at two significant figures)

Thus from the above conclusion we can say that The final temperature in Celsius of the metal block is 49°C.

Learn more about the Moles here: brainly.com/question/15356425

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7 0

2 years ago