How much water and how much 5. The volume does not need to be converted to liters yet because both sides of the equation use mL.
If In order for the scientist to make Water was added to 25 mL of a stock solution of 5. What is the molarity of the new solution? We are asked to find c 2 , which is the molarity of the diluted solution. Notice that all of the units for volume have been converted to liters.
Are you loving this? Not loving this? Please consider taking a moment to share your feedback with us. Students use the water displacement method to find the volume of different rods that all have the same mass. They calculate the density of each rod, and use the characteristic density of each material to identify all five rods.
Then students consider the relationship between the mass, size, and arrangement of atoms to explain why different rods have different densities. Students will be briefly introduced to the periodic table. Students will be able to explain that materials have characteristic densities because of the different mass, size, and arrangement of their atoms.
Students will be able to use the volume displacement method to find the volume of an object. Download the student activity sheet , and distribute one per student when specified in the activity. For this lesson you will need a set of five solid rods, each with the same mass, same diameter, but a different volume.
Each rod is made of a different material. There are several versions of these rods available from different suppliers. Since there are only five samples in the Equal Mass kit, you may need two kits so that each group can work with a sample. This chart will help you identify each rod. Do not reveal this information to the students. They will discover the identity of each rod and the inverse relationship between the density and the length of each rod later in this lesson.
Show students the five rods and explain that they all have the same mass. Then hold up the longest, middle-sized, and shortest rods and remind students that they have the same mass. Students may reason that since the mass of each rod is the same, the volume of each rod must have something to do with its density. Some may go so far as to say that the rod with the smallest volume must have the highest density, because the same mass is packed into the smallest volume.
Or that the rod with the largest volume must have the lowest density, because the same mass is spread out over the largest volume. Tell students that like the cubes in the previous activity, they will need to know the volume and mass of each of the samples. They will also calculate the density of each sample and use this value to figure out which material each rod is made of.
Project the animation Water Displacement. Play the animation as you demonstrate the water displacement method using a cup of water, a graduated cylinder, and a rod, the way students will do in the activity.
Use the dark gray plastic sample so that students can see it better. Tell students that the surface of water in a tube may not be completely flat. Instead, the surface may curve in a shallow U-shape called the meniscus. When measuring, read the line just at the bottom of the meniscus. Tilt the graduated cylinder and slowly slide the sample into the water.
Hold the graduated cylinder upright. Record the level of the water. Students will record their observations and answer questions about the activity on the activity sheet. The Explain It with Atoms and Molecules and Take It Further sections of the activity sheet will either be completed as a class, in groups, or individually, depending on your instructions.
Look at the teacher version of the activity sheet to find the questions and answers. Give students time to answer questions 1—5 on the activity sheet before starting the activity. What would be the concentration of a solution made by diluting What is the molarity of a solution that is made by diluting What volume of water would you add to See all questions in Dilution Calculations.
Impact of this question views around the world. You can reuse this answer Creative Commons License. The new pressure in the syringe is 2. It states that:. T 1 is the initial temperature. T 2 is the final temperature. This means that if a gas is heated up and the pressure does not change, the volume will.
As the pressure applied to a piston is doubled, the volume inside a cylinder is halved Because the volume has decreased, the particles will collide more frequently with the walls of the container.
0コメント