A gas cylinder contains 12 x 10²⁴ molecules of oxygen gas:

If Avogadro's number is 6x10²³; Calculate:

1. the mass of oxygen present in the cylinder.
2. the volume of oxygen at S.T.P. present in the
...

Action of cold and dilute Nitric acid on Copper.

Briefly explain the following term: Photophosphorylation

If an element has seven electrons in its outermost shell then it is likely to have the __________ (largest / smallest) atomic size among all the elements in the same period.

Give a geographical reason: Cotton is a labour-intensive crop.

Dry hydrogen chloride gas can be collected by ____ displacement of air. (downward / upward)

Which one of the following does not affect the rate of transpiration?

1. Light
2. Humidity
3. Wind
4. Age of the plant

Write the balanced chemical equation for the laboratory preparation of hydrogen chloride gas.

A man invests ₹22,500 in ₹50 shares available at 10% discount. If the dividend paid by the company is 12%, calculate:

1. The number of shares purchased
2. The annual dividend received.
3. The rate of return he gets on
...

Write the equation for the reaction that occurs at the cathode during the extraction of aluminum by electrolysis.

Explain briefly the territorial rearrangements as a result of World War I.

An effort is applied on the bigger wheel of a gear having 32 teeth. It is used to turn a wheel of 8 teeth. Where is it used?

Give two ways by which the trees that are found here have adapted to the climate.

The product of two consecutive natural numbers which are multiples of 3 is equal to 810. Find the two numbers.

In Period 3, the most metallic element is ____ . (sodium / magnesium / aluminium)

State the conditions required for total internal reflection of light to take place