Do now (5 minutes)Do now (5 minutes)

►Grab an Apron. Grab an Apron. ►There are some that are cut short for our There are some that are cut short for our

classmates. If you can use a longer apron, then classmates. If you can use a longer apron, then use it and leave the ones that are cut off for use it and leave the ones that are cut off for others.others.

►THANK YOU!THANK YOU!

What are standards and how are pH standard solutions prepared?

Do now/HWDo now/HW

►What do you think the letters in “pH” stand for? What do you think the letters in “pH” stand for? Give a reason for your answer.Give a reason for your answer.

►Hint: In yesterday’s lesson we spoke about the Hint: In yesterday’s lesson we spoke about the particular atoms are that make a solution acidic particular atoms are that make a solution acidic or basic.or basic.

What are standards and how are pH standard solutions prepared?

What are standards and how What are standards and how are pH standard solutions are pH standard solutions

prepared?prepared?

Mr. M. GonzalezMr. M. Gonzalez

What are standards and how are pH What are standards and how are pH standard solutions prepared?standard solutions prepared?

ObjectivesObjectives

►I can prepare calibrating solutions.I can prepare calibrating solutions.►I can measure volume using a graduated I can measure volume using a graduated

cylinder.cylinder.►I can prepare pH standards of 4, 7, and 10.I can prepare pH standards of 4, 7, and 10.

What are standards and how are pH standard solutions prepared?

MaterialsMaterials

► CalibrationCalibration Hanna Combo Meter (pH Hanna Combo Meter (pH

meter)meter) pH buffer capsules for pH 4, pH buffer capsules for pH 4,

7, and 107, and 10 Distilled waterDistilled water Graduated cylinderGraduated cylinder Stirring rod optionalStirring rod optional Jar with cap (greater than Jar with cap (greater than

100mL)100mL) Colored labeling tapeColored labeling tape Paper towelsPaper towels Apron and gogglesApron and goggles Non latex glovesNon latex gloves

What are standards and how are pH standard solutions prepared?

Fig. 01. Hanna Combo meter (pH).What are standards and how are pH standard

solutions prepared?

Fig. 02. Calibration StandardsWhat are standards and how are pH standard

solutions prepared?

Fig. 03. 1000mL beaker and squirt bottle.What are standards and how are pH standard

solutions prepared?

Fig. 04. Probe storage solution and probe.What are standards and how are pH standard

solutions prepared?

What are standard solutions?What are standard solutions?

►How are rulers made?How are rulers made?►There is a standard with which all rulers are There is a standard with which all rulers are

modeled after.modeled after.►A standard allows us to set a definition to a A standard allows us to set a definition to a

physical property and then repeat that physical physical property and then repeat that physical property over and over again.property over and over again.

What are standards and how are pH standard solutions prepared?

Preparing StandardsPreparing Standards

►Measure 100 ml of Measure 100 ml of filtered water.filtered water. Put graduated cylinder on Put graduated cylinder on

flat surfaceflat surface Level your eyes with the Level your eyes with the

surface of the water to surface of the water to read scale cylinderread scale cylinder

Water surface in cylinder Water surface in cylinder is curved (is curved (meniscusmeniscus) )

Read the volume at Read the volume at bottom of curvebottom of curve

What are standards and how are pH standard solutions prepared?

Converting ReviewConverting Review

1cubic centimeter 1cubic centimeter (cm(cm33)) = 1 Milliliter (mL) = 1 Milliliter (mL)

andand

1000 milliliters (mL) = 1 Liter (L)1000 milliliters (mL) = 1 Liter (L)

What are standards and how are pH What are standards and how are pH standard solutions prepared?standard solutions prepared?

Preparing StandardsPreparing Standards

►Add standard Add standard buffering powder to buffering powder to 100mL container.100mL container. Open containerOpen container Grab buffer “pill” ** Grab buffer “pill” **

between index fingers and between index fingers and thumbsthumbs

Twist off above containerTwist off above container Empty contents Empty contents

thoroughly into containerthoroughly into container

What are standards and how are pH standard solutions prepared?

** I will assign which ** I will assign which pill to groups.pill to groups.

Do now/HWDo now/HW

►What do you think the letters in “pH” stand for? What do you think the letters in “pH” stand for? Give a reason for your answer.Give a reason for your answer.

►Hint: In yesterday’s lesson we spoke about the Hint: In yesterday’s lesson we spoke about the particular atoms are that make a solution acidic particular atoms are that make a solution acidic or basic.or basic.

What are standards and how are pH standard solutions prepared?