How do you write 400000 in scientific notation?

A 25.0 ml sample of 0.723 m hclo4 is titrated with a 0.27303 m koh solution. the h3o+ concentration after the addition of 66.2 m

tia_tia [17]

This doesn't need an ICE chart. Both will fully dissociate in water.

Assume HClO4 and KOH reacts with one another. All you need to do is determine how much HClO4 will remain after the reaction. Calculate pH.

Step 1:

write out balanced equation for the reaction

HClO4+KOH ⇔ KClO4 + H2O

the ratio of HClO4 to KOH is going to be 1:1. Each mole of KOH we add will fully react with 1 mole of HClO4

Step 2:

Determining the number of moles present in HClO4 and KOH

Use the molar concentration and the volume for each:
25 mL of 0.723 M HClO4

Covert volume from mL into L:
25 mL * 1L/1000mL = 0.025 L

Remember:

M = moles/L so we have 0.025 L of 0.723 moles/L HClO4

Multiply the volume in L by the molar concentration to get:

0.025L x 0.723mol/L = 0.0181 moles HClO4.

Add 66.2 mL KOH with conc.=0.273M
66.2mL*1L/1000mL = .0662 L
.0662L x 0.273mol/L = 0.0181 moles KOH

Step 3:

Determine how much HClO4 remains after reacting with the KOH.

Since both reactants fully dissociate and are used in a 1:1 ratio, we just subtract the number of moles of KOH from the number of moles of HClO4:

moles HClO4 = 0.0181; moles KOH = 0.0181, so 0.0181-0.0181 = 0

This means all of the HClO4 is used up in the reaction.

If all of the acid is fully reacted with the base, the pH will be neutral = 7.

Determine the H3O+ concentration:

pH = -log[H3O+]; [H3O+] = 10-pH = 10-7

The correct answer is 1.0x10-7.

3 0

3 years ago

Read 2 more answers

How many moles are present in 54.8 mL of mercury if the density of mercury is 13.6 g/mL?

lesya692 [45]

Answer:

3.72 mol Hg

General Formulas and Concepts:

Chemistry - Atomic Structure

Reading a Periodic Table
Using Dimensional Analysis
Density = Mass over Volume

Explanation:

Step 1: Define

D = 13.6 g/mL

54.8 mL Hg

Step 2: Identify Conversions

Molar Mass of Hg - 200.59 g/mol

Step 3: Find

13.6 g/mL = x g / 54.8 mL

x = 745.28 g Hg

Step 4: Convert

$745.28 \ g \ Hg(\frac{1 \ mol \ Hg}{200.59 \ g \ Hg} )$ = 3.71544 mol Hg

Step 5: Check

We are given 3 sig figs. Follow sig fig rules and round.

3.71544 mol Hg ≈ 3.72 mol Hg

8 0

3 years ago

Hello! I just need a little bit of help. I'm supposed to design an experiment on how reaction rates are determined and affected

alexandr1967 [171]

Get 3 cups of water at the exact same temperature, using the thermometer to check.
Label the cups as ‘whole’, ‘pieces’, and ‘crushed’
Next, get something to dissolve, in this case, polident. Take one of the polident tablets and break it into 4 pieces, and set it aside.
Take another polident tablet and this time put it into a different cup, and crush it. Set it aside.
Keep the last tablet whole.
Set up your stopwatch and drop the polident tablet that is whole in the cup labeled ‘whole’, starting the stopwatch at the same time.
Watch the cup and see when the tablet is fully dissolved, then stop the stopwatch.
Record the time in the table.
Repeat steps 6-8 for both the ‘pieces’ and ‘crushed’ tablets.

Hope this helps! Please let me know if you need more help, or if you think my answer is incorrect. Brainliest would be MUCH appreciated. Have a great day!

Stay Brainy!

− $xXheyoXx$

3 0

2 years ago

Some amount of hydrogen peroxide (H2O2) breaks down to produce 3 molecules of oxygen (O2) and 6 molecules of water (H2O). How ma

soldier1979 [14.2K]

Answer:

$Atoms_H=12Atoms$

Explanation:

Hello,

In this case, the only source of hydrogen is in the 6 molecules of water, therefore, the atoms of hydrogen, by applying stoichiometry with the Avogadro's number is:

$Atoms_H=6moleculesH_2O*\frac{1molH_2O}{6.022x10^{23}moleculesH_2O}\frac{2molH}{1molH_2O}*\frac{6.022x10^{23}AtomsH}{1molH} \\Atoms_H=12Atoms$

Best regards.

3 0

3 years ago

Read 2 more answers

Ok, I need help with this one!!!!!!!!!!!!!!!!!!!! plz and thank you

Kitty [74]

Answer:

D)

Explanation:

3 0

4 years ago