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3 years ago

Question 18 of 35

Chemistry

1 answer:

sammy [17]3 years ago

4 0

Answer:

A. Dark-colored moths become common after tree trunks become

dark.

Explanation:

I took the test

You might be interested in

Lead (II) nitrate and magnesium iodide solutions are mixed

sashaice [31]

The molecular equation :

MgI₂(aq) + Pb(NO₃)₂(aq) → Mg(NO₃)₂(aq) + PbI₂(s)

The net ionic equations

Pb²⁺(aq) + 2I⁻(aq) → PbI₂(s)

<h3>Further explanation</h3>

Given

Word equation

Required

The molecular equations and the net ionic equations

Solution

The chemical equation can be expressed in terms of:

word equation
skeleton equation
balanced equation

The equation of a chemical reaction can be expressed in the equation of the ions

When a spectator ions are removed, the ionic equation is called the net ionic equation

A molecular equation is a chemical equation that has been balanced and is written in molecular (not ionic) form

The molecular equation :

MgI₂(aq) + Pb(NO₃)₂(aq) → Mg(NO₃)₂(aq) + PbI₂(s)

the ionic equation :

Mg²⁺ +2I⁻ + Pb²⁺ + 2NO₃⁻ → Mg²⁺ + 2NO₃⁻ + PbI₂

the net ionic equations

Pb²⁺(aq) + 2I⁻(aq) → PbI₂(s)

5 0

3 years ago

Bromine, a liquid at room temperature, has a boiling point of 58°C and a melting point of –7.2°C. Bromine can be classified as a

andreev551 [17]

Answer:

Pure substance.

Explanation:

7 0

3 years ago

Suppose of ammonium nitrate is dissolved in of a aqueous solution of sodium chromate. Calculate the final molarity of ammonium c

Marta_Voda [28]

Answer:

Final molarity of ammonium cation in the solution = 0.16 M

Explanation:

Complete Question

Suppose 2.59 g of ammonium nitrate is dissolved in 200. mL of a 0.40M aqueous solution of sodium chromate. Calculate the final molarity of ammonium cation in the solution. You can assume the volume of the solution doesn't change when the ammonium nitrate is dissolved in it. Be sure your answer has the correct number of significant digits.

Solution

2NH₄NO₃ + Na₂CrO₄ → (NH₄)₂CrO₄ + 2NaNO₃

We first convert the given parameters to number of moles

Number of moles = (Mass/Molar mass)

Molar mass of NH₄NO₃ = 80.043 g/mol

Number of moles of NH₄NO₃ = (2.59/80.043) = 0.03224 mole

Number of moles = (Concentration in mol/L) × (Volume in L)

Number of moles of Na₂CrO₄ = 0.4 × 0.2 = 0.08 Mole

2 moles of NH₄NO₃ react with 1 mole of Na₂CrO₄

So, it it evident that NH₄NO₃ is the limiting reagent as it is in short supply in the amount needed for the reaction.

So, the number of moles of ammonium ion in the product is also 0.03224 mole.

Molarity = (Number of moles)/(Volume L)

Molarity of ammonium ion = (0.03224/0.2) = 0.1612 mol/L = 0.16 M

Hope this Helps!!!

3 0

3 years ago

1. What do the ice ages tell us about how Earth's<br> climate has changed in the past?

Levart [38]

Answer:

During ice ages, the most characteristic change to the planet has been the formation and spread large ice sheets and glaciers across much the Northern Hemisphere.

3 0

3 years ago

How many moles of glucose does 1.2 x 10^24 molecules represent

sammy [17]

<h3>Answer:</h3>

2.0 mol C₆H₁₂O₆

<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>

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>

1.2 × 10²⁴ molecules C₆H₁₂O₆ (glucose)

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

Avogadro's Number

<u>Step 3: Convert</u>

Set up: $\displaystyle 1.2 \cdot 10^{24} \ molecules \ C_6H_{12}O_6(\frac{1 \ mol \ C_6H_{12}O_6}{6.022 \cdot 10^{23} \ molecules \ C_6H_{12}O_6})$
Divide: $\displaystyle 1.99269 \ mol \ C_6H_{12}O_6$

<u>Step 4: Check</u>

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

1.99269 mol C₆H₁₂O₆ ≈ 2.0 mol C₆H₁₂O₆

3 0

3 years ago