1. A sample of gold (Au) has a mass of 35.12 g.

1 answer:

galina1969 [7]4 years ago

8 0

a. Moles of gold = 35.12/197 = 0.18 moles. b. number of gold molecules = moles x 6.02 x 10^23 = 0.18 x 6.02 x 10^23= 1.08 x 10^23

You might be interested in

How does the number of valence electrons determine the type and number of bonds an element forms?

Advocard [28]

The number of electrons in an atom's outermost valence shell governs its bonding behaviour. Elements whose atoms have the same number of valence electrons are grouped together in the Periodic Table. ... Nonmetals tend to attract additional valence electrons to form either ionic or covalent bonds.

8 0

3 years ago

Why is photosynthesis essential for plant homeostasis?

nadya68 [22]

To make food for the plant

7 0

3 years ago

Which of the following best helps to why the value of Delta H degree for the CaF_2 in water in positive? A. CaF_2(s) is insolubl

FromTheMoon [43]

Answer: Option (C) is the correct answer.

Explanation:

A positive value of enthalpy or $\Delta H$ means that energy is being absorbed from the surrounding. As $CaF_{2}$ has strong ionic bonding between both calcium and fluorine atoms. So, to break their bond we need to provide energy to it.

So, when $CaF_{2}$ is dissolved in warm water then warm water molecules will bombard with the stable bond of $CaF_{2}$ . As a result, the energy will transfer from water to the bond in order to break it. And, due to loss in internal energy then there will be consequent lowering of temperature.

When this bond is broken down then the atoms will separates into gaseous ions and these ions will be then surrounded by the water molecules. As ithe bond between $CaF_{2}$ is very strong hence, its lattice energy will be very high.

Thus, we can conclude that the statement $Ca^{2+}$ ions have very strong interactions with $F^{-}$ ions in the crystal lattice, best helps to why the value of $\Delta H$ degree for the $CaF_{2}$ in water in positive.

7 0

3 years ago

Rufina [12.5K]

Answer:

massive flooding occurs in may at this location

Explanation:

i did the quiz idk if its right though :/

5 0

4 years ago

Which of the following best describes the change in Antarctic temperature from about 440,000 years ago to about 340,000 years ag

Vlada [557]

Answer: С . The temperature increases by about 12°C and then decreases by about 12°C.

Explanation:

Temperatures around the world have been on the rise since the Industrial revolution as humans clog the planet with Carbon Dioxide and other pollutants. This had led to a rise in temperatures that has seen ice levels fall and sea levels rise around the world.

Temperature fluctuations on the other hand are not a new thing. Studies show that in Antarctica temperatures from about 440,000 years ago to about 340,000 years ago increased by 12°C and then decreased by about 12°C.

7 0

3 years ago

Read 2 more answers