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3 years ago

How have safety concerns about chemicals changed over time?

Chemistry

1 answer:

Alex787 [66]3 years ago

8 0

Answer:

C. As scientists have learned more about chemicals, they have become more aware of their dangers

Explanation:

Chemicals are substances with standard compositions, held together by chemical bonds. Chemicals can exist in different phases such as solid, liquid, and gaseous phases. Over time, with a growing understanding of chemicals, their composition, and their reaction methods, scientists now have a better knowledge of the dangers chemicals can pose. To that effect, they have created standard safety measures for those who have to work with these chemicals.

When these guidelines are strictly adhered to, the chances of suffering accidents, burns, and explosions with these chemicals are significantly reduced.

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What is the different types of technology used for cloning animals?

gayaneshka [121]

There are three types of artificial cloning:
Gene cloning: copies a few segments of DNA or genes.
Reproductive cloning: it copies the whole animal.
Therapeutic cloning: produces embryonic stem cells for experiments aimed at creating tissues to replace injured or diseased tissues.

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3 years ago

Using the Hoffman apparatus for electrolysis, a chemist decomposes 2.3 moles of water into its gaseous elements. How many grams

solong [7]

Answer:

2.318032g

Explanation:

-The electrolysis equation of water is written as below:

$2H_2O_{(l)}->2H_2_{(g)}+O_2_{(g)}$

-The mole ratio of Water to the hydrogen formed is 1:1, therefore 2.3 moles of hydrogen gas is produced.

-Hydrogen's molar mass is 1.00784 grams:

$Mass=moles\times molar \ mass\\\\\=2.3\times 1.00784\\\\=2.318032\ g$

Hence, 2.318032 grams of hydrogen is produced.

7 0

3 years ago

How many molecules are in 42.3g sample of water

Helga [31]

Answer:

The number of molecules is 1.4140*10^24 molecules

Explanation:

To know the number of molecules, we need to determine how many moles of water we have, water has molar mass of 18.015g/mol

This means that one mole of water molecules has a mass of 18.015g.

42.3g * 1 mole H2O/18.015g

= 2.3480 moles H2O

We are using avogadros number to find the number of molecules of water

2.3480 H2O * 6.022*10^ 23moles/ 1mole of H2O

That's 2.3480 multiplied by 6.022*10^23 divided by 1 mole of H2O

Number of molecules = 1.4140 *10^24 molecules

5 0

2 years ago

During the combustion of methane (CH4), one mole of methane gas combines with two moles of oxygen gas (O2) to produce one mole o

astraxan [27]

Answer:

CH4(g) +2O2____ CO2(g) +2H2O (l)

3 0

2 years ago

When an electron falls from an excited state to ground state, is energy released or absorbed?

strojnjashka [21]

Answer:

Energy is released.

Explanation:

When an electron absorbs energy, it moves up into an excited state. When it releases energy, it will return to the ground state.

5 0

2 years ago