CHEM 111 LAB EXP (3)

An antacid tablet was dissolved in water and 10mL of 0.16M HCl was added. After the acid had reacted with the tablet it required 40mL of 0.02M NaOH to neutralize the HCl that remained. How many grams of HCl (Molar Mass = 36.5 g/mol) did the antacid neutralize?

0.029

When the following chemical equation is balanced: __Mg(OH)2(s) + __HCl(aq) = __MgCl2(aq) + __H2O(l) The stoichiometric co-efficients are

1,2,1,2

An antacid tablet was dissolved in water and 10mL of 0.16M HCl was added. After the acid had reacted with the tablet it required 40mL of 0.02M NaOH to neutralize the HCl that remained. How many moles of HCl were initially added to the antacid?

1.6x10-3

What is the approximate molarity of the HCl used in this experiment.

1M

An antacid tablet was dissolved in water and 10mL of 0.16M HCl was added. After the acid had reacted with the tablet it required 40mL of 0.02M NaOH to neutralize the HCl that remained. How many moles of HCl did the antacid neutralize?

8.0x10-4

An antacid tablet was dissolved in water and 10mL of 0.16M HCl was added. After the acid had reacted with the tablet it required 40mL of 0.02M NaOH to neutralize the HCl that remained. How many moles of NaOH were required to neutralize the HCl that remained after it had reacted with the tablet?

8.0x10-4

In this experiment what do you use to dispense the acid into the Erlenmeyer flask?

A repipet

When you react hydrochloric acid and sodium hydroxide you get

A salt and water

The reaction: HCl(aq) + NaOH(aq) = NaCl(aq) + H2O(l) is an example of a(n):

Acid-base reaction

If during Trial P, upon addition of only a few mL of NaOH the indicator changes color you should

Add more HCl, reheat, and continue with the titration

In this experiment, all the acid added is neutralized by

An antacid and sodium hydroxide

The purpose of this experiment is to

Determine the number of moles of acid neutralized by an antacid tablet.

A back titration is used in this experiment. This is because

Many antacids contain more than one active ingredient

How is the number of moles of acid neutralized by the antacid determined in this experiment?

Moles of acid added - moles of acid remaining

To determine the number of moles of acid that were initially added to the Erlenmeyer

Multiply the molarity of the HCl by the volume in Liters of HCl added

Which of the following is not a common active ingredient in commercial antacids?

NaOH

In reading a buret, you should always

Read the bottom of the meniscus

When the tablet has reacted completely with the acid

Some inert binder will remain in the flask and the solution may be cloudy

When the phenolphthalein changes color, then

The amount of NaOH added is just sufficient to react with all the acid present

The purpose of Trial T is

To get an idea of the expected end-point and the amount of HCl to add in subsequent trials