The atomic mass can be smaller than the atomic number

what volume of carbon 4 oxide measured at STP will produce when 21 gram of sodium hydrogen carbonate for is completely decompose

Arlecino [84]

The volume of CO₂ at STP = 2.8 L

<h3>Further explanation</h3>

Given

21 gram of sodium hydrogen carbonate-NaHCO₃

Required

Volume of CO₂

Solution

The decomposition of sodium bicarbonate into sodium carbonate, carbon dioxide, and water :

<em> 2 NaHCO₃(s) → Na₂CO₃(s) + CO₂(g) + H₂O(g)</em>

mol of NaHCO₃ :

= mass : MW NaHCO₃

= 21 g : 84 g/mol

= 0.25

From the equation, mol ratio of NaHCO₃(s) :CO₂(g) = 2 : 1, so mol CO₂ :

= 1/2 x mol NaHCO₃

= 1/2 x 0.25

= 0.125

At STP, 1 mol gas = 22.4 L, so for 0.125 mol :

= 0.125 x 22.4 L

= 2.8 L

8 0

3 years ago

What is the density of a book with a mass of 60g and a volume of 20 cm3?

Vaselesa [24]

Answer:

2.5 g/cm3 .

Explanation:

Density is mass in grams over volume in cubic centimeters. So it is 25 g 10 cm 3 =2.5 g/cm 3 The unit is grams per cubic centimeter. NB - density can also be kilograms over cubic meters Hope this helps!

6 0

3 years ago

Given the following unbalanced equation:

Lorico [155]

<h3>Answer:</h3>

8.01 mol MgO

<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> </u>

<u>Chemistry</u>

<u>Atomic Structure</u>

Moles
Compounds

<u>Stoichiometry</u>

Using Dimensional Analysis
Analyzing Reactions RxN

<h3>Explanation:</h3>

<u>Step 1: Define</u>

[RxN - Unbalanced] Mg + O₂ → MgO

[RxN - Balanced] 2Mg + O₂ → 2MgO

[Given] 8.01 moles Mg

[Solve] moles MgO

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

[RxN] 2 mol Mg → 2 mol MgO

<u>Step 3: Stoich</u>

[DA] Set up: $\displaystyle 8.01 \ mol \ Mg(\frac{2 \ mol \ MgO}{2 \ mol \ Mg})$
[DA] Multiply/Divide [Cancel out units]: $\displaystyle 8.01 \ mol \ MgO$

3 0

3 years ago

Which of these elements have the same number of valance electrons

solmaris [256]

Both carbon and lead belong to Group IV elements, and thus they have the same number of valence electrons.
<span>In each of the other options, the two elements belong to different groups, and thus they do NOT have the same number of valence electrons.

I hope this helped you, please tell me if I am correct or not <3
</span>

6 0

4 years ago

In the Hall-Heroult process, a large electric current is passed through a solution of aluminum oxide Al2O3 dissolved in molten c

gtnhenbr [62]

Answer:

1.13 × 10⁶ g

Explanation:

Let's consider the reduction of aluminum (III) from Al₂O₃ to pure aluminum.

Al³⁺ + 3 e⁻ → Al

We can establish the following relations:

1 Ampere = 1 Coulomb / second
The charge of 1 mole of electrons is 96,468 c (Faraday's constant)
1 mole of Al is produced when 3 moles of electrons circulate
The molar mass of Al is 26.98 g/mol.

The mass of aluminum produced under these conditions is:

$90.0 s \times \frac{1s}{620c} \times \frac{96,468c}{1mole^{-} } \times \frac{3mole^{-}}{1molAl} \times \frac{26.98gAl}{1molAl} =1.13 \times 10^{6} g Al$

6 0

4 years ago