Questions on maths mechanics

What is the molarity of a solution that contains 0.400 mol HCl in 9.79 l solution?

Maslowich

Answer:

Option B, 0.0409 M

Explanation:

1) Data:

a) M = ?

b) n = 0.400 mol

V = 9.79 liters

2) Formula:

M = n / V (in liters)

3) Solution:

M = 0.400 mol / 9.79 liter = 0.04086 M

Since each data contain 3 significant digits, the answer must be reported with 3 significant digits. So, the correct answer is 0.0409 M, which is the option B.

8 0

4 years ago

In the simulation, open the micro mode, then select solutions indicated below from the dropdown above the beaker in the simulati

Rzqust [24]

Milk (lowest acidity) < Coffee < Orange juice < Soda pops < vomit < Battery acid (highest acidity)

explanation :

pH values of all :

battery acid pH = 1.0

vomit pH = 2.0

soda pop pH = 2.5

orange juice pH = 3.5

coffee pH = 5.0

milik pH = 6.5

pH value is lesser acidity is more . high pH indicate lesser acidic nature

3 0

3 years ago

What is the empirical formula of a compound that is 24.42 % calcium, 17.07 % nitrogen, and 58.5% oxygen?

REY [17]

Answer:

$CaN_{2} O_{6}$

Explanation:

When calculating an empirical formula from percentages, assume you have a 100g sample. This allows you to convert the percentages directly to grams, because X % of 100g is X grams.

So:

24.42 % = 24.42 g Ca, 17.07% = 17.07g N, 58.5% = 58.5g O

The next step is to divide each mass by their molar mass to convert your grams to moles.

24.42/40.08 = 0.6092 mol

17.07/14.01 = 1.218 mol

58.85/15.99 = 3.680 mol

Then you will divide all of your mol values by the SMALLEST number of moles. This gives you whole numbers that are the mole ratio (subcripts) of the empircal formula.

0.6092 mol/0.6092 mol = 1

1.218 mol/0.6092 mol = 2

3.680 mol/0.6092 mol = 6

So the empirical formula is $CaN_{2} O_{6}$

5 0

3 years ago

What is the total number of atoms in this formula? NaHCO3

Pavel [41]

6 - one sodium atom, 1 hydrogen atom, 1 carbon atom, and 3 oxygen atoms.

7 0

4 years ago

2. In Experiment SOL, you investigated the solubility of oxalic acid. Sodium oxalate, Na2C2O¬4, is the sodium salt of this acid.

AnnZ [28]

Answer:

Sodium oxalate is a basic salt. In water it can be dissolved and dissociated.

The oxalic acid in water has two dissociations.

Explanation:

Na2C2O4 ---> 2Na+ + C2O4-2

Sodium oxalate is the conjugate base of a weak acid. In water this salt, dissociates completely giving rise to the sodium and oxalate ions. As Na+ comes from a strong base, in water it does not produce hydrolysis while oxalate does react in water, because it takes a proton from it and it generates a basic hydrolysis releasing OH-.

C2O4-2 + H2O ⇄ HC2O4- + OH-

In water the salt is basic. The pH of an aqueous solution of this salt is basic, since OH- is generated.

The HC2O4- has a second hydrolisis, it takes another proton from water to form oxalic acid.

HC2O4- + H2O ⇄ H2C2O4 + OH-

The oxalic acid acts as a weak acid, it can release 2 protons to water, to make oxalate (its conjugate base).

H2C2O4 + H2O ⇄ H3O+ + HC2O4-

HC2O4- + H2O ⇄ H3O+ C2O4-2

The HC2O4- acts as an ampholyte since it accepts and delivers protons simultaneously.

6 0

4 years ago