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### Re: Forensics C

Posted: August 1st, 2015, 3:35 pm
pikachu4919 wrote:
samlan16 wrote:Well, it's been a while since anyone posted on this question marathon, so...

How can you tell the difference between sodium carbonate and sodium bicarbonate?
`they have different pH values. Na2CO3's is 10 and NaHCO3's is 8.`
Correct! Please post the next question.

### Re: Forensics C

Posted: August 4th, 2015, 3:52 pm
How can one make sure a flame test result is or isn't actually yellow?

### Re: Forensics C

Posted: August 4th, 2015, 6:27 pm
pikachu4919 wrote:How can one make sure a flame test result is or isn't actually yellow?
`Look at the flame with cobalt blue glass to filter out any orange/ yellow light from the flames.`

### Re: Forensics C

Posted: August 4th, 2015, 8:05 pm
samlan16 wrote:
pikachu4919 wrote:How can one make sure a flame test result is or isn't actually yellow?
`Look at the flame with cobalt blue glass to filter out any orange/ yellow light from the flames.`

### Re: Forensics C

Posted: August 5th, 2015, 8:19 am
Suppose that you are given a powder which burns red in a standard propane flame. What is the cation in that compound?

### Re: Forensics C

Posted: August 6th, 2015, 12:53 pm
samlan16 wrote:Suppose that you are given a powder which burns red in a standard propane flame. What is the cation in that compound?
`Li +`

### Re: Forensics C

Posted: August 6th, 2015, 12:56 pm
yellow_squirtle wrote:
samlan16 wrote:Suppose that you are given a powder which burns red in a standard propane flame. What is the cation in that compound?
`Li +`
Correct!

### Re: Forensics C

Posted: August 6th, 2015, 1:09 pm
Light travels from air into a glass fragment with an angle of incidence of 42 degrees. The angle of refraction at the end of the fragment is 18 degrees.
Calculate the index of refraction of the glass. Round to the nearest hundredth.

### Re: Forensics C

Posted: August 6th, 2015, 1:20 pm
yellow_squirtle wrote:Light travels from air into a glass fragment with an angle of incidence of 42 degrees. The angle of refraction at the end of the fragment is 18 degrees.
Calculate the index of refraction of the glass. Round to the nearest hundredth.
```asinθ1=bsinθ2
b=asinθ1/sinθ2
=asin42°/sin18°
a=1.00
∴ b=2.17```

### Re: Forensics C

Posted: August 6th, 2015, 5:36 pm
samlan16 wrote:
yellow_squirtle wrote:Light travels from air into a glass fragment with an angle of incidence of 42 degrees. The angle of refraction at the end of the fragment is 18 degrees.
Calculate the index of refraction of the glass. Round to the nearest hundredth.
```asinθ1=bsinθ2
b=asinθ1/sinθ2
=asin42°/sin18°
a=1.00
∴ b=2.17```
Correct.