An average cup of coffee contains about 125 mg caffeine- C8H10N4O2- 6-44- 10-x moles of caffeine are in a cup- Then- the value of x is-

Moles of caffeine =125×10^ 3Molar mass = 125×10^ 3194 #160;= 6.44×10^ 4 .So, value of x is 4 . ...

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard XII

Chemistry

Stoichiometric Calculations

An average cu...

Question

An average cup of coffee contains about $125$ mg caffeine, $C_{8} H_{10} N_{4} O_{2}$ , $6.44 \times 10^{- x}$ moles of caffeine are in a cup. Then, the value of $x$ is:

Open in App

Solution

Moles of caffeine $= \frac{125 \times 10^{- 3}}{M o l a r m a s s} = \frac{125 \times 10^{- 3}}{194} = 6.44 \times 10^{- 4}$ .

So, value of $x$ is $4$ .

Suggest Corrections

Similar questions

Q. The average cup of tea contains ........ mg of caffeine.

Arabic coffee, or “Qahwah” is a very important drink in the Gulf region and in the Middle East generally. It refers to a version of brewed coffee beans that contains spices like cardamom and saffron. Qahwah is usually consumed without sugar. Finjan is a small delicate cup (typically of 25 mL volume) that is traditionally used to serve this Arabic coffee. During celebrations and gatherings, half-filled Finjans of Arabic coffee are served several times to guests. An average Finjan contains about 4.10 mg of caffeine, C8H10N4O2. How many molecules of caffeine are there in a half-filled Finjan?

Q. What is empirical formula of the following-
Caffeine

(C_{8} H_{10} N_{4} O_{2})

a substance found in tea and coffee.

Q. Caffeine present in the coffee is a/an

Q. Caffeine (Mol. wt. = 194) contains 28.9% of nitrogen. How many number of nitrogen atoms are present in one molecule of caffeine?

Join BYJU'S Learning Program

An average cup of coffee contains about 125 mg caffeine, C8H10N4O2, 6.44×10−x moles of caffeine are in a cup. Then, the value of x is:

Moles of caffeine =125×10−3Molarmass=125×10−3194=6.44×10−4.So, value of x is 4.

An average cup of coffee contains about $125$ mg caffeine, $C_{8} H_{10} N_{4} O_{2}$ , $6.44 \times 10^{- x}$ moles of caffeine are in a cup. Then, the value of $x$ is:

Moles of caffeine $= \frac{125 \times 10^{- 3}}{M o l a r m a s s} = \frac{125 \times 10^{- 3}}{194} = 6.44 \times 10^{- 4}$ .

So, value of $x$ is $4$ .