Isotopes are atoms of an element

If someone is watching someone watching the tv and hes watching someone watching the tv and the other one is watching someone wa

belka [17]

then they are all watching tv XD

8 0

4 years ago

Read 2 more answers

The density of water is 1.00g/ml at 4 degrees Celsius.How many water molecules are present in 2.56ml of water at this temperatur

vivado [14]

Answer:

8.55x10^22 molecules

Explanation:

From the question given, the following data were obtained:

Density = 1g/mL

Volume = 2.56mL

Mass =?

Density = Mass /volume

Mass = Density x volume

Mass = 1 x 2.56

Mass = 2.56g

Now let us convert this mass (i.e 2.56g) of water to mole

Molar Mass of H2O = (2x1) + 16 = 2 + 16 = 18g/mol

Mass of H2O = 2.56g

Number of mole of H2O=? Number of mole = Mass /Molar Mass

Number of mole of H2O = 2.56/18

Number of mole of H2O = 0.142mol

From Avogadro's hypothesis, 1mole of any substance contains 6.02x10^23 molecules. This means that 1mole of H2O contains 6.02x10^23 molecules.

Now if 1mole of H2O contains 6.02x10^23 molecules, then 0.142mol of H2O will contain = 0.142 x 6.02x10^23 = 8.55x10^22 molecules

6 0

4 years ago

A certain liquid has a normal freezing point of and a freezing point depression constant . Calculate the freezing point of a sol

katrin2010 [14]

The question is incomplete, the complete question is:

A certain liquid X has a normal freezing point of $0.80^oC$ and a freezing point depression constant $K_f=7.82^oC.kg/mol$ . Calculate the freezing point of a solution made of 81.1 g of iron(III) chloride () dissolved in 850. g of X. Round your answer to significant digits.

Answer: The freezing point of the solution is $-17.6^oC$

Explanation:

Depression in the freezing point is defined as the difference between the freezing point of the pure solvent and the freezing point of the solution.

The expression for the calculation of depression in freezing point is:

$\text{Freezing point of pure solvent}-\text{freezing point of solution}=i\times K_f\times m$

OR

$\text{Freezing point of pure solvent}-\text{Freezing point of solution}=i\times K_f\times \frac{m_{solute}\times 1000}{M_{solute}\times w_{solvent}\text{(in g)}}$ ......(1)

where,

Freezing point of pure solvent = $0.80^oC$

Freezing point of solution = $?^oC$

i = Vant Hoff factor = 4 (for iron (III) chloride as 4 ions are produced in the reaction)

$K_f$ = freezing point depression constant = $7.82^oC/m$

$m_{solute}$ = Given mass of solute (iron (III) chloride) = 81.1 g

$M_{solute}$ = Molar mass of solute (iron (III) chloride) = 162.2 g/mol

$w_{solvent}$ = Mass of solvent (X) = 850. g

Putting values in equation 1, we get:

$0.8-(\text{Freezing point of solution})=4\times 7.82\times \frac{81.1\times 1000}{162.2\times 850}\\\\\text{Freezing point of solution}=[0.8-18.4]^oC\\\\\text{Freezing point of solution}=-17.6^oC$

Hence, the freezing point of the solution is $-17.6^oC$

6 0

3 years ago

Why did hurricane Katrina slow down at data point 7 ?

adell [148]

Answer:

Because the hot air from the equator is balance with the cold air from the polar region, meaning the temperature is the right degree, therefore it causes the slowing down of that hurricane.

Explanation:

From your science class you do study the convectional current right? that's what happen on the outside real life

3 0

4 years ago

What controls flowering in many plants?

katrin2010 [14]

Answer:

All flowering is regulated by the integration of environmental cues into an internal sequence of processes. These processes regulate the ability of plant organs to produce and respond to an array of signals. The numerous regulatory switches permit precise control over the time of flowering.

Explanation:

3 0

3 years ago