Which group of elements are considered to be in the same family?

How many particles of CuCr2O7 are present in a 64.5 gram sample?

kow [346]

<h3>Answer:</h3>

1.39 × 10²³ particles CuCr₂O₇

<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>

Reading a Periodic Table
Moles
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

<u>Stoichiometry</u>

Using Dimensional Analysis

<h3>Explanation:</h3>

<u>Step 1: Define</u>

[Given] 64.5 g CuCr₂O₇

[Solve] particles CuCr₂O₇

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

Avogadro's Number

[PT] Molar Mass of Cu - 63.55 g/mol

[PT] Molar Mass of Cr - 52.00 g/mol

[PT] Molar Mass of O - 16.00 g/mol

Molar Mass of CuCr₂O₇ - 63.55 + 2(52.00) + 7(16.00) = 279.55 g/mol

<u>Step 3: Convert</u>

[DA] Set up: $\displaystyle 64.5 \ g \ CuCr_2O_7(\frac{1 \ mol \ CuCr_2O_7}{279.55 \ g \ CuCr_2O_7})(\frac{6.022 \cdot 10^{23} \ particles \ CuCr_2O_7}{1 \ mol \ CuCr_2O_7})$
[DA] Divide/Multiply [Cancel out units]: $\displaystyle 1.38944 \cdot 10^{23} \ particles \ CuCr_2O_7$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 3 sig figs.</em>

1.38944 × 10²³ particles CuCr₂O₇ ≈ 1.39 × 10²³ particles CuCr₂O₇

8 0

3 years ago

Sodium peroxide (Na2O2) is often used in self-contained breathing devices, such as those used in fire emergencies, because it re

Anastaziya [24]

Answer:

725.15 L

Explanation:

The balanced chemical equation for the reaction between Na₂O₂ and CO₂ is the following:

Na₂O₂ + CO₂ → Na₂CO₃ + 1/2 O₂

From the stoichiometry of the reaction, 1 mol of Na₂O₂ reacts with 1 mol CO₂. So, the stoichiometric ratio is 1 mol Na₂O₂/1 CO₂.

Now, we convert the mass of reactants to moles by using the molecular weight (Mw) of each compound:

Mw (Na₂O₂) = (23 g/mol x 2) + (16 g/mol x 2) = 78 g/mol

moles Na₂O₂ = 96.7 g/(78 g/mol) = 1.24 mol Na₂O₂

Mw (CO₂) = 12 g/mol + (16 g/mol x 2) = 44 g/mol

moles CO₂ = 0.0755 g/(44 g/mol) = 1.71 x 10⁻³ mol CO₂

Now, we calculate the number of moles of CO₂ we need to completely react with the mass of Na₂O₂ we have:

1.24 mol Na₂O₂ x 1 mol CO₂/1 mol Na₂O₂ = 1.24 mol CO₂

In 1 L of respired air we have 1.71 x 10⁻³ mol CO₂ (0.0755 g), so we need the following number of liters to have 1.24 mol of CO₂:

1.24 mol CO₂ x 1 L/1.71 x 10⁻³ mol CO₂ = 725.15 L

4 0

3 years ago

What reaction type is depicted by the following equation? 2C2H2 + 5O2 4CO2 + 2H2O decomposition combination combustion single-re

Vladimir [108]

combustion is when you burn something in presence e of oxygen and the products will be mainly the CO2 and H2O

3 0

3 years ago

Read 2 more answers

What does a balanced equation allows you to determine

Allushta [10]

It allows you to determine the relation between the reactants and the products.

7 0

3 years ago

Which substance has a high melting point and conducts electricity in the liquid phase

ELEN [110]

It is true that substances that have a high melting point and conduct electricity in the liquid phase are ionic substances, and if one of your options is NaCl, then that is the correct answer.

8 0

3 years ago

Read 2 more answers