HELP! A. W B. X C. Y D. Z

If y > z, which of the following equations must be true?

marin [14]

Answer:

I think the answer is y-z>0

8 0

3 years ago

Calculate the molar mass of cacl2

kirza4 [7]

Answer:

$\boxed {\boxed {\sf 110.98 \ g/mol}}$

Explanation:

The molar mass is the mass of a substance in grams per mole.

To find it, add the mass of each element in the compound. These masses can be found on the Periodic Table.

The compound given is:

$CaCl_2$

The compound has 1 Ca (calcium) and 2 Cl (chlorine).

Mass of Calcium

The molar mass of calcium is 40.08 g/mol
There is only one atom of Calcium in CaCl₂, so the number above is what we will use.

Mass of Chlorine

The molar mass of chlorine is 35.45 g/mol
There are two atoms of chlorine in CaCl₂, therefore we need to multiply the molar mass by 2.
35.45 * 2= 70.9 g/mol

Molar Mass of CaCl₂

Now, to find the molar mass, add the molar mass of 1 calcium and 2 chlorine.
40.08 g/mol + 70.9 g/mol =110.98 g/mol

The molar mass of CaCl₂ is 110.98 grams per mole.

6 0

3 years ago

5. A penny weighs about 2.5 g. How many moles of pennies would be required to equal the mass of the moon (7.3x10^24 kg)

schepotkina [342]

5. 1.16 x $10^{26}$ moles moles of pennies would be required to equal the mass of the moon.

6. 12.86 moles of ethanol are in a 750 ml bottle of vodka.

Explanation:

5 .Data given:

mass of penny = 2.5 grams

atomic mass of penny = 62.93 grams/mole

moles present in mass of the moon given as = 7.3 x $10^{24}$ kg

number of moles = $\frac{mass}{atomic mass of 1 mole}$

number of moles = $\frac{2.5}{62.93}$

0.039 moles of penny is present in 2.5 grams

0.039 moles of penny in 2.5 grams of it

so, x moles in 7.3 X $10^{27}$ grams

$\frac{0.039}{2.5} =\frac{x}{7.3 X 10^{27} }$

x = 1.16 x $10^{26}$ moles

so when the mass of the penny given is equal to the mass of moon, number of moles of penny present is 1.1 x $10^{26}$ .

6.

Given:

vodka = 40% ethanol

volume of vodka bottle = 750 ml

moles of ethanol =?

density of ethanol =0.79 g/ml

atomic mass of ethanol = 46.07 grams/mole

so, from the density of ethanol given we can calculate how much ethanol is present in the solution.

density = $\frac{mass}{volume}$

density x volume = mass

0.79 x 750 = 592.5 grams

number of moles = $\frac{mass}{atomic mass of 1 mole}$

number of moles of ethanol = $\frac{592.5}{46.07}$

= 12.86 moles of ethanol

6 0

2 years ago

Key words how atoms work?

pantera1 [17]

Most atoms have three different subatomic particles inside them: protons, neutrons, and electrons. The protons and neutrons are packed together into the center of the atom(which is called the nucleus) and the electrons, which are very much smaller, whizz around the outside. Most of an atom is empty space.

I hope this helps you! :D

3 0

2 years ago

Match the following descriptions with the correct polysaccharide, note if you answer any part of this question incorrectly a sig

Ad libitum [116K]

Answer:

Glycogen. Cellulose. Amylose. Cellulose. Amylopetin and Glycogen. Amylopetin and Cellulose.

Explanation:

Glycogen is the form that glucose is stored in human body.

Cellulose is the structural part of plant cell walls and human cannot digest it.

Amylose is the polysaccharide linked mainly by the the bonds of $\alpha$ 1,4 glycosidic.

Cellulose is an unbranched polysaccharide linked mainly by the bonds of $\beta$ 1,4 glycosidic.

Amylopetin and Glycogen are branched polysaccharides linked by the bonds of $\alpha$ 1,4 glycosidic and $\alpha$ 1,6 glycosidic.

Amylopetin and Cellulose are mainly stored in plants.

4 0

3 years ago