Which equipment would help you separate a liquid mixture by distillation?

Scientists recently discovered that firing low-energy particles at potatoes keeps the potatoes

vodomira [7]

Answer:

By allowing the potatoes to be stored longer so they can be sold during winter months.

Explanation:

Since low energy particles are fired at the potatoes to prevent them from developing unwanted sprouts, it means that it prevents sprouts from growing on the potatoes.

Now, winter is wet period which encourages more growth of the sprouts. Thus, the way this development will affect the industry is that the potatoes will be stored for longer period and then sold in the winter.

6 0

3 years ago

Francium is an extremely rare alkali metal, many of whose physical properties

bazaltina [42]

Answer:

136 neutrons

87 protons

Explanation:

A neutral atom have equal number of protons and neutrons. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The number of protons or number of electrons are the atomic number of an atom while the number of protons and number of neutrons are the mass number of an atom. Every atom consist of nucleus or a positive center. The protons and neutrons are present with in the nucleus while electrons are present out side the nucleus. All these three subatomic particles construct an atom.

Example:

In Francium the number of proton and neutron can be found by subtracting the atomic number of francium from its atomic mass. The atomic number will be the number of protons and remaining will show the total number of neutrons present in nucleus.

Atomic number is 87

Atomic mass 223

223- 87 = 136

So number of neutrons are 136 and number of protons are 87.

6 0

3 years ago

An aqueous solution of sodium fluoride is slowly added to a water sample that contains barium ion (2.75×10-2M ) and calcium ion

Alona [7]

Answer : The remaining concentration of the first ion to precipitate when the second ion begins to precipitate is, $1.07\times 10^{-6}M$

Explanation :

The dissociation of barium fluoride is written as:

$BaF_2\rightleftharpoons Ba^{2+}+2F^-$

The expression for solubility constant for this reaction will be,

$K_{sp}=[Ba^{2+}][F^-]^2$

As we know that at room temperature $25^oC$ the $K_{sp}$ of barium fluoride is, $1\times 10^{-6}$ .

Now put all the given values in this expression, we get:

$1\times 10^{-6}=(2.75\times 10^{-2})\times [F^-]^2$

$[F^-]=6.03\times 10^{-3}M=0.00603M$

The barium fluoride precipitate when fluoride ion is equal to 0.00603 M.

The dissociation of calcium fluoride is written as:

$CaF_2\rightleftharpoons Ca^{2+}+2F^-$

The expression for solubility constant for this reaction will be,

$K_{sp}=[Ca^{2+}][F^-]^2$

As we know that at room temperature $25^oC$ the $K_{sp}$ of calcium fluoride is, $3.90\times 10^{-11}$ .

Now put all the given values in this expression, we get:

$3.90\times 10^{-11}=(6.70\times 10^{-2})\times [F^-]^2$

$[F^-]=2.41\times 10^{-5}M=0.0000241M$

The calcium fluoride precipitate when fluoride ion is equal to 0.0000241 M.

Since, the fluoride ion concentration in calcium fluoride is less then the fluoride ion concentration in barium fluoride. That means, calcium fluoride will precipitate first.

Thus, the concentration $Ca^{2+}$ ion remaining at $F^-$ concentration (0.00603 M) is calculated as: