All categories

3 years ago

How many moles 30.56g of Ca(OH)

Chemistry

1 answer:

Ostrovityanka [42]3 years ago

8 0

Answer:

0.412 moles

Explanation:

No of moles =given mass /molar mass

30.56/74=0.412 moles

Note these are the number of moles of

Ca(OH)2 not Ca(OH)

You might be interested in

2.3 Zinc has five naturally occurring isotopes: 48.63% of 64 Zn with an atomic weight of 63.929 amu; 27.90% of 66Zn with an atom

lakkis [162]

Answer: The average atomic mass of element Zinc is 65.40 amu.

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$ .....(1)

For $_{30}^{64}\textrm{Zn}$ isotope:

Mass of $_{30}^{64}\textrm{Zn}$ isotope = 63.929 amu

Percentage abundance of $_{30}^{64}\textrm{Zn}$ isotope = 48.63 %

Fractional abundance of $_{30}^{64}\textrm{Zn}$ isotope = 0.4863

For $_{30}^{66}\textrm{Zn}$ isotope:

Mass of $_{30}^{66}\textrm{Zn}$ isotope = 65.926 amu

Percentage abundance of $_{30}^{66}\textrm{Zn}$ isotope = 27.90 %

Fractional abundance of $_{30}^{66}\textrm{Zn}$ isotope = 0.2790

For $_{30}^{67}\textrm{Zn}$ isotope:

Mass of $_{30}^{67}\textrm{Zn}$ isotope = 66.927 amu

Percentage abundance of $_{30}^{67}\textrm{Zn}$ isotope = 4.10 %

Fractional abundance of $_{30}^{67}\textrm{Zn}$ isotope = 0.0410

For $_{30}^{68}\textrm{Zn}$ isotope:

Mass of $_{30}^{68}\textrm{Zn}$ isotope = 67.925 amu

Percentage abundance of $_{30}^{68}\textrm{Zn}$ isotope = 18.75 %

Fractional abundance of $_{30}^{68}\textrm{Zn}$ isotope = 0.1875

For $_{30}^{70}\textrm{Zn}$ isotope:

Mass of $_{30}^{70}\textrm{Zn}$ isotope = 69.925 amu

Percentage abundance of $_{30}^{70}\textrm{Zn}$ isotope = 0.62 %

Fractional abundance of $_{30}^{70}\textrm{Zn}$ isotope = 0.0062

Putting values in equation 1, we get:

$\text{Average atomic mass of Zinc}=[(63.929\times 0.4863)+(65.926\times 0.2790)+(66.927\times 0.0410)+(67.925\times 0.1875)+(69.925\times 0.0062)]$

$\text{Average atomic mass of Zinc}=65.40amu$

Hence, the average atomic mass of element Zinc is 65.40 amu.

7 0

4 years ago

According to nature of flow, convective heat transfer is classified into natural convection

Brrunno [24]

Answer:

When the motion of the fluid results due to natural means like the buoyancy effect, that is, the elevation of the warmer fluid and the fall of the cooling fluid is termed as natural convection. Boiling water is the everyday illustration of the natural convection, in the process, the passing of the heat takes place from the burner into the pot, and heats the water present at the bottom.

On the other hand, when the fluid is forced to flow in a tube or over the surface by external means like with the help of a fan or a pump is termed as forced convection. The use of a fan on a hot summer day is an everyday illustration of forced convection. An example of effective heat transfer is the sweat produced by our body. Therefore, when one switches off the fan, the air present around the body captivates the water vapor until it gets saturated. It takes place for some time and stops eventually, which makes one feel hotter.

At that time, when the fan is switched back again, the air surrounding the body starts to move again, without completely getting saturated, and thus, evaporation of the sweat takes place that also contains the heat of the body and one feels cooler.

6 0

3 years ago

Choose the answer below that gives the correct chemical symbol and classification (metal, metalloid, or nonmetal) for the elemen

Zielflug [23.3K]

Answer: B. The element called tin is a metal with the chemical symbol Sn.

Explanation:

A is incorrect because Ni is Nickel, not Niobium.

C is incorrect because Carbon is a nonmetal and its symbol is C, not Cr.

D is incorrect because Copper's symbol is Cu, not Ce.

E is incorrect because As is the symbol for Arsenic, not Astatine.

6 0

3 years ago

What is the formula equation for the reaction between sulfuric acid and dissolved sodium hydroxide if all products and reactants

Varvara68 [4.7K]

The formula equation for the reaction between sulfuric acid and dissolved sodium hydroxide will be the same even if all products and reactants are in the aqueous or in the liquid phase. It is as follows:

H2SO4 + 2NaOH = Na2SO4 + 2H2O

8 0

4 years ago

Read 2 more answers

What is the molarity of a solution that contains 12 moles of solute and 583 ml of solution?

frozen [14]

Answer:

21 M

Explanation:

Molarity = mol solute/ L solution = 12 mol/0.583 L ≈ 21 mol/L = 21 M

5 0

3 years ago