The density of a 20.0% by mass ethylene glycol (C 2 H 6 O 2 ) solution in water is 1.03 g/mL. Find the molarity of the solution.

Hey everyone. So today we are asked to calculate the polarity of a 70% weight by weight per chlorate acid solution in water. And were given that the density of the solution Is 1.67 g per mil a leader. So for this question we need to use the polarity formula polarity. And using the information given within the question, we can find the two values that we need for this. We can find the moles of solute or h C L 04 folkloric acid and our leaders of solution, leaders of solution. So to start off for the sake of this problem, we can assume that we have 100 g of total solution Because then 70% of this, our 70% weight by weight of preclearance acid. It's just simply 70 g of ACL 04, it just makes their calculations a lot easier. And using the periodic table, we can determine that the molar mass of is 100 . grams per mole. So to then convert the grams the mass of hcl four that we have two molds of folkloric acid. We can use some quick stoking metric conversions before multiply this by the inverse smaller mass. One mole over 100. cramps. And that will leave us with 0.69 grams. Sorry malls of Hcl 04 of pro clark acid. Now to find the leaders of solution, we need to use the density rho Which is 1. grams for milliliters. Right? And remember that density is nothing more than mass by volume. So to find the volume. Therefore the volume is equal to the mass by the density. And we can use the mass that we assumed earlier or 100 g of solution here as well. So let's calculate that. So this will be 100 g per one point or sorry, divided by air. My bad 1.67 grams per milliliter. And our grams will cancel out. And we'll be left with an answer of 59 point 88 milliliters. But we're not done here. We need our volume and leaders so we can recall that we have 10 to the negative 3rd leaders For every one millim. So we can actually multiply this by our volume or sorry, volume that we just calculated 59.88 mm And will reach a value of 0. L. So bringing this back to our polarity, the polarity is equal to 0. 968 more each. Cielo four divided by 0.05988 L of solution Which will give us an answer of 11.6 molar 11.6 Molar

Ch.4 - Chemical Quantities & Aqueous Reactions

All textbooks

Tro 4th Edition

Ch.4 - Chemical Quantities & Aqueous Reactions

Problem 101

Chapter 4, Problem 101

The density of a 20.0% by mass ethylene glycol (C₂H₆O₂) solution in water is 1.03 g/mL. Find the molarity of the solution.

Verified step by step guidance

Calculate the mass of ethylene glycol in 1 liter of solution. Since the density is 1.03 g/mL, 1 liter (1000 mL) of solution weighs 1030 grams. With a 20.0% by mass concentration, the mass of ethylene glycol can be calculated as 20.0% of 1030 grams.

Convert the mass of ethylene glycol to moles. The molar mass of ethylene glycol (C₂H₆O₂) is calculated by adding the molar masses of carbon (12.01 g/mol), hydrogen (1.008 g/mol), and oxygen (16.00 g/mol). Use this molar mass to convert the mass of ethylene glycol to moles.

Calculate the volume of the solution in liters. Since the density is given and you have the mass of the solution, use the formula: Volume = Mass / Density.

Calculate the molarity of the solution using the formula: Molarity = Moles of solute / Volume of solution in liters.

Ensure all units are consistent (grams, moles, liters) throughout the calculations to avoid any errors in the final molarity.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Density

Density is defined as mass per unit volume, typically expressed in grams per milliliter (g/mL) or kilograms per cubic meter (kg/m³). In this context, the density of the solution helps to relate the mass of the solution to its volume, which is essential for calculating molarity. Understanding how to manipulate density allows for the conversion between mass and volume, a crucial step in determining the concentration of a solution.

Molarity

Molarity is a measure of concentration defined as the number of moles of solute per liter of solution (mol/L). It is a key concept in solution chemistry, allowing chemists to quantify how much solute is present in a given volume of solution. To find the molarity of the ethylene glycol solution, one must calculate the number of moles of ethylene glycol and divide it by the total volume of the solution in liters.

Mass Percent Concentration

Mass percent concentration is a way to express the concentration of a solution, calculated as the mass of solute divided by the total mass of the solution, multiplied by 100. In this case, the 20.0% by mass indicates that there are 20 grams of ethylene glycol in every 100 grams of solution. This concept is important for determining the amount of solute present, which is necessary for calculating molarity when combined with the solution's density.