All categories

2 years ago

. How many grams of Na2SO4 are required to make 2700 mL of a 2.0 M solution?

Chemistry

2 answers:

ratelena [41]2 years ago

6 0

Answer:

Explanation:

From the net ionic equation

Ba2+(aq) + SO42-(aq) ==> BaSO4(s) we see that 1 mole Ba2+ reacts with 1 mole SO42- to -> 1 mol BaSO4

Find moles of Ba2+ used: 0.250 moles/L x 0.0323 L = 0.008075 moles Ba2+

Find moles SO42- present: 0.008075 moles Ba2+ x 1 mol SO42-/1 mol Ba2+ = 0.008075 mol SO42-

Find mass of Na2SO4 present: 0.008075 mol SO42- x 1 mol Na2SO4/1 mol SO42- x 142.04 Na2SO4/mole = 1.14698 g = 1.15 g Na2SO4 (to 3 significant figures)

Andru [333]2 years ago

6 0

Answer: Approx 2kg of salt are required.

Explanation: If 4.5 ⋅ L of a 3.0 ⋅ m o l ⋅ L − 1 solution are required, this is a molar quantity of 4.5 ⋅ L × 3.0 ⋅ m o l ⋅ L − 1 = 13.5 ⋅ m o l . Now, we simply multiply this molar quantity by a molar mass to get the mass: 13.5 ⋅ m o l × 142.04 ⋅ g ⋅ m o l − 1 = ? ? ⋅ g

You might be interested in

Put the elements in order from lowest (1) to highest (6) electronegativity.

bogdanovich [222]

(1) Francium - 0.7 Lowest
(2) Barium - 0.89
(3) Aluminium- 1.61
(4) Copper - 1.90
(5) Phosphorus - 2.19
(6) Flurorine - 3.98 Highest electronegativity in periodic lable

8 0

3 years ago

If hydrofluoric acid is a stronger acid than acetic acid, which statement is most likely true?

Alchen [17]

Answer: The statement conjugate base of hydrofluoric acid is weaker than that of acetic acid is most likely true.

Explanation:

A strong acid upon dissociation gives a weak conjugate base. This can also be said as stronger is the acid, weaker will be its conjugate base or vice-versa.

Hydrofluoric acid is a strong base as it dissociates completely when dissolved in water.

For example, $HF \rightleftharpoons H^{+} + F^{-}$

The conjugate base is $F^{-}$ which is a weak base.

Acetic acid is a weak acid as it dissociates partially when dissolved in water. So, the conjugate base of acetic acid is a strong base.

$CH_{3}COOH \rightarrow CH_{3}COO^{-} + H^{+}$

Thus, we can conclude that the statement conjugate base of hydrofluoric acid is weaker than that of acetic acid is most likely true.

4 0

3 years ago

Please help me please

sweet-ann [11.9K]

Explanation:

1 sugar solution =Distillation

2 Iron powder and sand=magnetic separation

3 petrol and diesel= Fractional distillation

4 Camphor and glass powder = Sublimation

7 0

3 years ago

Determine the volume, in liters, occupied by 0.050 moles of water vapor at STP.

hoa [83]

Answer:

delete this answer please

4 0

3 years ago

Calculate the number of atoms in 2.5 moles of Si.

Ede4ka [16]

Answer:

$\boxed {\boxed {\sf About \ 1.5 * 10^{24} \ atoms \ Si}}$

Explanation:

When converting from moles to atoms, we must use Avogadro's number. This number tells us there are 6.022 * 10²³ atoms in 1 mole. We can multiply this number by the number of moles.

First, we must set up Avogadro's number as a ratio.

$\frac {6.022 \ * 10^{23} \ atoms \ Si }{1 \ mol \ Si}}$

Next, multiply the number of moles by the ratio.

$2.5 \ mol \ Si *\frac {6.022 \ * 10^{23} \ atoms \ Si }{1 \ mol \ Si}}$

When we multiply, the moles of silicon will cancel.

$2.5 * \frac {6.022 \ * 10^{23} \ atoms \ Si }{1}}$

Since the denominator of the fraction is 1, we can cancel it out too.

$2.5 * {6.022 \ * 10^{23} \ atoms \ Si }$

$1.5055 * 10^{24} \ atoms \ Si$

The original measurement (2.5 moles) has 2 significant figures (2 and 5). Therefore we must round to 2 sig figs. For this question, 2 sig figs is the tenth place.

The 0 in the hundredth place tells us to leave the 5 in the tenth place.

$1.5 * 10^{24} \ atoms \ Si$

There are about <u>1.5 * 10²⁴ atoms of silicon.</u>

7 0

3 years ago