How many moles are in 4.5 g of Sodium Chloride, NaCl?

1. If we used 0.0100 moles of K2CO3, how many moles of SrCO3 can be expected to form?

faltersainse [42]

Answer:

0.01 moles of SrCO₃

Explanation:

In this excersise we need to propose the reaction:

K₂CO₃ + Sr(NO₃)₂ → 2KNO₃ + SrCO₃

As we only have data about the potassium carbonate we assume the strontium nitrite as the excess reactant.

1 mol of K₂CO₃ react to 1 mol of Sr(NO₃)₂ in order to produce 2 moles of potassium nitrite and 1 mol of strontium carbonate.

Ratio is 1:1. In conclussion,

0.01 mol of K₂CO₃ must produce 0.01 moles of SrCO₃

3 0

3 years ago

A 52.0-mL volume of 0.35 M CH3COOH (Ka=1.8×10−5) is titrated with 0.40 M NaOH. Calculate the pH after the addition of 23.0 mL of

Rus_ich [418]

52.0ml of 0.35M CH3COOH : 0.052 L(0.35M) = .0182 mol of CH3COOH.

31.0ml of 0.40M NaOH : .031 L(0.40M) = .0124 mol of NaOH.

After the reaction, .0124 Mol CH3COO- is generated and .058 mol CH3COOH is left un-reacted. The concentration would be 12.4/V and 5.8/V, respectively. Therefore:


pH = -log([H+]) = -log(Ka*[CH3COOH]/[CH3COO-]) 
= -log(1.8x10^-5*5.8/12.4) = 5.07

6 0

3 years ago

What is the most specific classification of Ca(NO3)2

Cerrena [4.2K]

"Compound" is the one among the following choices given in the question that is the most specific classification of Ca(NO3)2. The correct option among all the options that are given in the question is the second option. It is actually an inorganic compound. I hope that this is the answer that has come to your help.

7 0

3 years ago

Read 2 more answers

PLEASE HELP QUICK!! WILL MARK BRAINLIEST ANSWER!! When water is diffused across a selectively permeable membrane, scientists ref

xxTIMURxx [149]

Answer :

During diffusion, when the concentration of the molecules on both sides of the membrane is the same, the molecules will continue to move across the membrane in both the direction.

Answer 3 : It allows single-celled organism to reproduce, and other organism to repair damage tissues and grow.

Answer 4: The nucleus is an organelle that is surrounded by the cytoplasm, a jelly-like fluid.

Explanation :

Diffusion : It is a process where liquid moves from higher concentration to the lower concentration through permeable membrane.

When the concentration of the molecules on both sides of the membrane is same and the membrane is permeable membrane then diffusion will occur and the molecules will moves continuously across the membrane in both the direction.

Answer 3 :

Mitosis : It is a process of cell division. In this process, nucleus divides into two daughter cell and each daughter cell contains same number of chromosomes as present in parent nucleus.

The main purpose of the mitosis is to repair damaged tissues and growth.

Answer 4 :

Nucleus is a type of cell organelle. It is present in both animal and plant cells and it is the brain of the cell. It is present only in eukaryotic cell.

Nucleus is an organelle which is surrounded by the cell membrane which protects its from the other cells.

Cytoplasm is a jelly-like fluid which is present in the cell membrane which is made up of salt and water.

7 0

3 years ago

If you have access to stock solutions of 1.00 M H3PO4, 1.00 M of HCl, and 1.00 M NaOH solution, (and distilled water of course),

garri49 [273]

Answer:

0.10L of 1.00M of H₃PO₄ and 0.1613L of 1.00M NaOH

Explanation:

The pKa's of phosphoric acid are:

H₃PO₄/H₂PO₄⁻ = 2.1

H₂PO₄⁻/HPO₄²⁻ = 7.2

HPO₄²⁻/PO₄³⁻ = 12.0

To make a buffer with pH 9.40 we need to convert all H₃PO₄ to H₂PO₄⁻ and an amount of H₂PO₄⁻ to HPO₄²⁻

To have a 50mM solution of phosphoures we need:

2L * (0.050mol / L) = 0.10 moles of H₃PO₄

0.10 mol * (1L / mol) = 0.10L of 1.00M of H3PO4

To convert the H₃PO₄ to H₂PO₄⁻ and to HPO₄²⁻ must be added NaOH, thus:

H₃PO₄ + NaOH → H₂PO₄⁻ + H₂O + Na⁺

H₂PO₄⁻ + NaOH → HPO₄²⁻ + H₂O + Na⁺

Using H-H equation we can find the amount of NaOH added:

pH = pKa + log [A⁻] / [HA] (1)

Where [A-] is conjugate base, HPO₄²⁻ and [HA] is weak acid, H₂PO₄⁻

pH = 7.40

pKa = 7.20

[A-] + [HA] = 0.10moles (2)

Replacing (2) in (1):

7.40 = 7.20 + log 0.10mol - [HA] / [HA]

0.2 = log 0.10mol - [HA] / [HA]

1.5849 = 0.10mol - [HA] / [HA]

1.5849 [HA] = 0.10mol - [HA]

2.5849[HA] = 0.10mol

[HA] = 0.0387 moles = H₂PO₄⁻ moles

That means moles of HPO₄²⁻ are 0.10mol - 0.0387moles = 0.0613 moles

The moles of NaOH needed to convert all H₃PO₄ in H₂PO₄⁻ are 0.10 moles

And moles needed to obtain 0.0613 moles of HPO₄²⁻ are 0.0613 moles

Total moles of NaOH are 0.1613moles * (1L / 1mol) = 0.1613L of 1.00M NaOH

Then, you need to dilute both solutions to 2.00L with distilled water.

4 0

3 years ago