A drop of water has a volume of approximately 0.05 mL. How many water molecules does it contain? The density of water is 1.0 g/cm³.

검증된 단계별 안내

First, convert the volume of the water drop from milliliters to cubic centimeters (cm3) since the density of water is given in g/cm3. Remember that 1 mL is equivalent to 1 cm3.

Next, use the density of water to convert the volume of the water drop to mass. Density is defined as mass per unit volume, so you can multiply the volume of the water drop by the density of water to find the mass of the water drop in grams.

Then, convert the mass of the water drop to moles using the molar mass of water. The molar mass of water (H2O) is approximately 18.015 g/mol. You can do this by dividing the mass of the water drop by the molar mass of water.

After that, use Avogadro's number to convert the number of moles of water to the number of water molecules. Avogadro's number (6.022 x 10^23) is the number of particles (atoms, molecules, ions, etc.) in one mole of a substance.

Finally, calculate the number of water molecules in the drop of water by multiplying the number of moles of water by Avogadro's number.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

도움이 되었나요?

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Molar Mass of Water

The molar mass of water (H2O) is approximately 18.02 g/mol. This value is essential for converting grams of water to moles, which allows us to relate the mass of water to the number of molecules it contains. Since one mole of any substance contains Avogadro's number of entities (approximately 6.022 x 10^23), knowing the molar mass is crucial for calculating the total number of water molecules in a given volume.

Density and Volume Relationship

Density is defined as mass per unit volume, and for water, it is approximately 1.0 g/cm³. This means that 1 mL of water has a mass of about 1 gram. Understanding this relationship allows us to convert the volume of water (0.05 mL) into mass, which is necessary for further calculations involving the number of molecules.

Avogadro's Number

Avogadro's number (6.022 x 10^23) is the number of atoms, ions, or molecules in one mole of a substance. This constant is fundamental in chemistry for converting between moles and the number of individual particles. Once we determine the number of moles of water from its mass, we can use Avogadro's number to find the total number of water molecules present in the drop.

A drop of water has a volume of approximately 0.05 mL. How many water molecules does it contain? The density of water is 1.0 g/cm3.