Question about Texas Instruments TI-30XA Calculator

# When I go to use the 'log' button on TI 30XA I do not come up with the same answer as in my course book (for the examples) No real instructions on logs in the little instruction book. Have tried every permutation I can think of - help in how to use it please!! Trying to work out pH levels Thanks, Sue.

Posted by on

• kakima May 17, 2011

Could you post an example, giving the keystrokes you're using?

×

Ad

## 1 Answer

• Level 3:

An expert who has achieved level 3 by getting 1000 points

Superstar:

An expert that got 20 achievements.

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

• Texas Instru... Master
• 7,993 Answers

You calculate the pH with the relation
pH=-log(c) where c is the value of concentration in mol/L.
ex: c[H+]= 3.57x10^(-6)
pH: (-) [LOG] 3.57 [2nd][EE] [(-)] 6 [ ) ]
Here you have 2 change sign key press [(-)]

If you have the pH, and want to calculate the concentration that yields that value of the pH you proceed as follows
c= 10^(-pH)
Ex pH=8.23
c: [2nd][LOG] [(-) 8.23 [)]

General shortcut.
If concentration is of the form c[H+]= 1*10^(-a) where a is an integer between 0 and 14, the pH is equal to the positive value of exponent.

Ex:c[H+]=1x10^(-5) Mol/L then the pH is just the positive value of the exponent, ie 5 because pH=-log(1.x10^-5) =- log1 -log(10^-5)=0 -(-5)=5
Above I use the rule log(axb)=log(a)+log(b) , the rule log(a^b) = b*log(a)and the facts that log(1)=0 and log(10)=1, the last being true if log stands for log in base 10.

Posted on Jun 09, 2011

Ad

## 1 Suggested Answer

• 2 Answers

Hi,
a 6ya Technician can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Technician (only for users in the US for now) and get all the help you need.
Goodluck!

Posted on Jan 02, 2017

Ad

## Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video.

×

Loading...

## Related Questions:

2 Answers

### Cubic root button

not sure what you want,cubic root button is like a tick with a line at the top

Jan 09, 2012 | Texas Instruments TI-30XA Calculator

1 Answer

### If an equation would require dividing by log ( which og course can't be done) what button is used to fulfil that equation?

Of course you can divide by a log. As an example, to divide 2 by the log of 3, press
2 / 3 LOG =
To divide 2 by the natural log of 3, press
2 / 3 LN =

Oct 27, 2011 | Texas Instruments TI-30XA Calculator

1 Answer

### Hi, how do i calculate log^-1 on my ti-30xa? for example, in order to calculate log^-1(-2), what do i do? thank you.

The inverse of the common log function is the power function with base 10 (10^). It shares the same physical key as the log. You acees the function by pressing [2nd] [log]

Sep 09, 2011 | Texas Instruments TI-30XA Calculator

1 Answer

### Now that I know where the square root button is on my TI-30Xa, how do I calculate a "geometric mean" when the equation inclues a time period? For example the problem is setup like this: 6...

You don't want the square root. In this example, you want the sixth root.

Press 4 5 2nd [xth-root] 6 =

The xth-root is the shifted function of the y^x key, located just above the divide key.

Jun 11, 2011 | Texas Instruments TI-30XA Calculator

1 Answer

### How do you use TAN, SIN, and COS on this calculator?

I'm going to use sin(90°) as an example. You would hit the sin button, type in 90, then hit ). You must type in the close parenthesis or the calculator won't read it correctly. The answer should be 1.

Jun 08, 2011 | Texas Instruments TI-30XA Calculator

1 Answer

### How do I convert from decimals to fraction with my TI-30X IIS calculator? I need the step by step process

The following examples will demonstrate how to convert decimals into fractions using the TI-30Xa and TI-30Xa Solar. Please be aware that TI-30Xa Solar School Edition calculators do not have this functionality.

Example: Convert .25 to 1/4
- Input .25, press [2nd][<--] (says F<>D above it).

** F<>D means fraction to decimal, decimal to fraction.

Example: Convert 1.38 to 1_19/50

- Input 1.38, press [2nd][<--].

Example: Convert 9.75 to 9_3/4

- Input 9.75, press [2nd]{<--].

Mar 08, 2011 | Texas Instruments TI-30XA Calculator

1 Answer

### Using the correct key combination to determine inverse log

Hi,
Sorry to contradict you but there are many types of logarithms, the most important ones are
1. the common logarithms (log in base 10),
2. the natural logarithms (logarithms in base e)
3. the binary logarithms (logarithms in base 2)
On calculators, the common logarithms are labeled [LOG], and the natural logarithms are labeled [LN].

The inverse function of the natural log function is the exponential (e^(x)), and the inverse of the log in base ten function is the function ten to the power of. It is called (sometimes) the antilog

Ex:
Question What is the antilog of 3.5678?
Answer The antilog of 3.5678 is 10^(3.5678) = 3696.579068
Verification: log(3696.57908) =3.5678

Hope it helps.

Nov 29, 2009 | Texas Instruments TI-30XA Calculator

1 Answer

### Antilog in chemistry problem

pH is minus (log to base 10) of the hydrogen ion activity of an aqueous solution, or (log to base 10) of (1/hydrogen ion activity)

To get the inverse log, i.e the hydrogen ion activity corresponding to a specified pH, simply enter the pH value and press

2nd
LOG
1/x

Answer 0.001

Apr 22, 2008 | Texas Instruments TI-30XA Calculator

1 Answer

### Difficulty changing to the Statistics mode

Download the small instruction book from TI web site, keystrokes and examples at pages 10/11

http://education.ti.com/educationportal/downloadcenter/SoftwareList.do?website=US&tabId=2&paneId=18

Mar 22, 2008 | Texas Instruments TI-30XA Calculator

## Open Questions:

#### Related Topics:

206 people viewed this question

## Ask a Question

Usually answered in minutes!

Level 3 Expert

102366 Answers

Level 2 Expert

265 Answers

Level 3 Expert

17130 Answers

Loading...