All categories

4 years ago

The student's lab manual says to mix some of his Na2CO3 solution with an aqueous solution of copper(II) sulfate (CuSO4)

Chemistry

1 answer:

lord [1]4 years ago

3 0

Explanation:

When the student mixed the solution sodium carbonate with solution of copper(II) sulfate ; Copper Hydroxocarbonate , sodium sulfate and carbon dioxide gas was obtained as a products.

The balanced chemical reaction

$2Na_2CO_3+2CuSO_4\rightarrow Cu_2(OH)_2CO_3+2Na_2SO_4+CO_2$

Where:

$Cu_2(OH)_2CO_3$ = Copper(II) Hydroxocarbonate

$Na_2CO_3$ = Sodium carbonate

$CuSO_4$ = Copper(II) sulfate

$Na_2SO_4$ = Sodium sulfate

$CO_2$ = Carbon-dioxide

You might be interested in

Caffeine (C8H10N4O2) is a weak base with a pKb of 10.4. Calculate the pH of a solution containing a caffeine concentration of 41

RSB [31]

Answer:

pH → 7.47

Explanation:

Caffeine is a sort of amine, which is a weak base. Then, this pH should be higher than 7.

Caffeine + H₂O ⇄ Caffeine⁺ + OH⁻ Kb

1 mol of caffeine in water can give hydroxides and protonated caffeine.

We convert the concentration from mg/L to M

415 mg = 0.415 g

0.415 g / 194.19 g/mol = 2.14×10⁻³ mol

[Caffeine] = 2.14×10⁻³ M

Let's calculate pH. As we don't have Kb, we can obtain it from pKb.

- log Kb = pKb → 10^-pKb = Kb

10⁻¹⁰'⁴ = 3.98×10⁻¹¹

We go to equilibrium:

Caffeine + H₂O ⇄ Caffeine⁺ + OH⁻ Kb

Initially we have 2.14×10⁻³ moles of caffeine, so, after the equilibrium we may have (2.14×10⁻³ - x)

X will be the amount of protonated caffeine and OH⁻

Caffeine + H₂O ⇄ Caffeine⁺ + OH⁻ Kb

(2.14×10⁻³ - x) x x

We make the expression for Kb:

3.98×10⁻¹¹ = x² / (2.14×10⁻³ - x)

We can missed the -x in denominator, because Kb it's a very small value.

So: 3.98×10⁻¹¹ = x² / 2.14×10⁻³

√(3.98×10⁻¹¹ . 2.14×10⁻³) = x → 2.92×10⁻⁷

That's the [OH⁻]. - log [OH⁻] = pOH

- log 2.92×10⁻⁷ = 6.53 → pOH

14 - pOH = pH → 14 - 6.53 = 7.47

4 0

3 years ago

A dark purple liquid is diluted by adding water.

alexandr402 [8]

Answer: The process is diffusion.

Explanation:

a dark liquid will have the highest concentration of dark purple atoms/molecules so it gives a concentrated colour.

when water is added to it, the colourless water molecules fill up the gaps between the purple particles and so their colour fades and becomes lighter and lighter as we add more water. see the image attached where imagine the red particles are water and the blue particles are purple particles. thats why the colour fades.

6 0

1 year ago

If the map shows the average high temperature in July for two cities in Texas. like Del Rio=36°c

Sedbober [7]

Answer:

Explanation:

Ocean breezes keep coastal galveston cooler than Del Rio, which is inland exposed to southerly winds.

4 0

3 years ago

The atmosphere surrounding Earth helps to maintain the various climates found around the world and keeps Earth from becoming ext

riadik2000 [5.3K]

Answer:

The atmosphere traps heat energy from the Sun and energy radiated from Earth's surface helping to maintain Earth's climate

Explanation:

Earth's atmosphere keeps much of the Sun's energy from escaping into space. This process, called the greenhouse effect, keeps the planet warm enough for life to exist. The atmosphere allows about half of the Sun's heat energy (50%) to reach Earth's surface.

4 0

3 years ago

How many moles of sand (SiO2) are in 30 g of sand?

anastassius [24]

<h3>Answer:</h3>

0.50 mol SiO₂

<h3>General Formulas and Concepts:</h3>

<u>Math</u>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

<u>Chemistry</u>

<u>Atomic Structure</u>

Reading a Periodic Table
Using Dimensional Analysis

<h3>Explanation:</h3>

<u>Step 1: Define</u>

30 g SiO₂ (sand)

<u>Step 2: Identify Conversions</u>

Molar Mass of Si - 28.09 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of SiO₂ - 28.09 + 2(16.00) = 60.09 g/mol

<u>Step 3: Convert</u>

Set up: $\displaystyle 30 \ g \ SiO_2(\frac{1 \ mol \ SiO_2}{60.09 \ g \ SiO_2})$
Multiply/Divide: $\displaystyle 0.499251 \ mol \ SiO_2$

<u>Step 4: Check</u>

<em>Follow sig figs and round. We are given 2 sig figs.</em>

0.499251 mol SiO₂ ≈ 0.50 mol SiO₂

5 0

3 years ago

Read 2 more answers