"Configuration of a Certain Concentration Solution" PPT courseware

Description

"Configuration of a Certain Concentration Solution" PPT courseware

Initial experience

Method 1: Solute + water, salt and water

Method 2: Concentrated solution + water 20% salt water plus water

Method three: dilute solution + solute 10% salt water plus salt

Method 4: Mix concentrated solution + dilute solution 20% and 10% salt water

Method 5: Evaporate water from dilute solution 10% salt water evaporates water

Purpose

1. Practice preparing solutions with a certain solute mass fraction.

2. Deepen your understanding of the concept of mass fraction of solute.

Experimental supplies

Pallet balance, beaker, glass rod, medicine spoon, measuring cylinder, plastic tip dropper, narrow-mouth bottle

sodium chloride, distilled water

Related knowledge links:

1. Calculation of solute mass fraction:

Mass fraction of solute = ---------- ×100%

Mass of solute =___________ ×___________

Solvent mass = ___________ - ________

2. When a concentrated solution is diluted with water

(1) The mass of the solute in the concentrated solution = the mass of the solute in the dilute solution (fill in >, <, =).

(2) The mass of water used = the mass of dilute solution – the mass of concentrated solution.

3. Use of pallet balance

(1) Leveling method:

First set the scale to ______ on the ruler, and then adjust the left and right _________ to balance the scale.

(2) How to use:

When weighing a certain mass of medicine, first _____ the balance, then use tweezers to add a certain mass of weight to _____, and move the weight if necessary; use a medicine spoon to gradually add medicine to _____ until the balance is balanced. After weighing, ______ put the weight box back and _____ return it to zero.

(3) When weighing dry pharmaceuticals:

Place a piece of __________ paper on each of the two trays, and weigh the medicines on the paper.

Preparing a solution with a certain solute mass fraction is a required content in the junior high school chemistry high school entrance examination instructions. It is not only an important experiment in the junior high school chemistry experimental operation assessment, but also a hot topic in the high school entrance examination in recent years.

1. Experimental principle

1. Solute mass fraction = mass of solute/(mass of solute + mass of solvent) × 100%

2. Dilution of solution:

m (concentrated solution) × a% = m (dilute solution) × b% (a>b)

2. Experimental instruments

Pallet balance, measuring cylinder, beaker, glass rod, medicine spoon, dropper

3. Experimental steps

1. Calculation: Calculate the required amount of solute and solvent according to the preparation requirements (the required mass of solid sodium chloride is 3g, and the required volume of water is 47ml).

2. Weighing or measuring: Weighing refers to weighing the mass of solid substances; (the mass of sodium chloride is 3g) measuring refers to measuring the volume of liquid substances (the volume of water is 47ml).

3. Dissolve: Mix the solute salt and solvent water and stir until fully dissolved.

4. Bottle: Put the prepared 6% sodium chloride solution into the reagent bottle and label it.

4. Error analysis

1. The relationship between the change in the mass of the actual dissolved solute and the change in the solute mass fraction

(1) The amount of dissolved solute is reduced: the solute itself is impure; less solute is weighed (weighing objects on the left and right)

(After weighing, the pointer moves to the right) (When the balance is unloaded, the pointer moves to the left); the solute is spilled; the solute is bottled and stored before it is completely dissolved.

(2) The amount of solute dissolved increases: more solute is weighed, (the pointer moves to the left) (when the balance is unloaded, the pointer moves to the right)

2. The relationship between changes in the mass of the actual solvent used and changes in the mass fraction of the solute

(1) The amount of solvent is reduced: measure from above; the solvent is not completely transferred to the beaker; liquid splashes out when dissolving.

(2) The amount of solvent increases: look up to measure; there is water on the inner wall of the beaker; there is water on the inner wall of the reagent bottle

Keywords: Teaching courseware for the configuration of a solution of a certain concentration, download the PPT courseware for the first volume of the ninth grade chemistry of the Hunan Education Edition, download the courseware for the ninth grade chemistry slideshow, download the PPT courseware for the configuration of a solution of a certain concentration, .PPT format;

For more information about the "Configuration of Certain Concentration Solutions" PPT courseware, please click the "Configuration of Certain Concentration Solutions ppt" tab.

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Update Time: 2024-10-04

This template belongs to Chemistry courseware Hunan Education Edition Ninth Grade Chemistry Volume 1 industry PPT template

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