What is 1.5 x 10^3 in standard notation

luminum and oxygen react according to the following equation: 4Al(s) +3O2(g) --> 2Al2O3(s) What mass of Al2O3, in grams, can

Slav-nsk [51]

Answer: 8.7 grams

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}=\frac{4.6g}{27g/mol}=0.17moles$

$4Al(s)+3O_2(g)\rightarrow 2Al_2O_3(s)$

As oxygen is in excess, Aluminium is the limiting reagent and limits the formation of products.

According to stoichiometry:

4 moles of aluminium give = 2 moles of $Al_2O_3(s)$

Thus 0.17 moles of aluminium give= $\frac{2}{4}\times 0.17=0.085mol$

Mass of $Al_2O_3=moles\times {\text {molar mass}}=0.085\times 102g/mol=8.7g$

Thus the mass of $Al_2O_3(s)$ is 8.7 grams

8 0

3 years ago

A solution was prepared by dissolving 0.800 g of sulfur S8, in 100.0 g of acetic acid, HC2H3O2. Calculate the freezing point and

sammy [17]

Answer: The freezing point of solution is 16.5°C and the boiling point of solution is 118.2°C

Explanation:

To calculate the molality of solution, we use the equation:

$Molality=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ in grams}}$

Where,

$m_{solute}$ = Given mass of solute $(S_8)$ = 0.800 g

$M_{solute}$ = Molar mass of solute $(S-8)$ = 256.52 g/mol

$W_{solvent}$ = Mass of solvent (acetic acid) = 100.0 g

Putting values in above equation, we get:

$\text{Molality of solution}=\frac{0.800\times 1000}{256.52\times 100.0}\\\\\text{Molality of solution}=0.0312m$

Calculation for freezing point of solution:

Depression in freezing point is defined as the difference in the freezing point of water and freezing point of solution.

$\Delta T_f=\text{freezing point of acetic acid}-\text{Freezing point of solution}$

To calculate the depression in freezing point, we use the equation:

$\Delta T_f=iK_fm$

or,

$\text{Freezing point of acetic acid}-\text{Freezing point of solution}=iK_fm$

where,

Freezing point of acetic acid = 16.6°C

i = Vant hoff factor = 1 (for non-electrolyte)

$K_f$ = molal freezing point depression constant = 3.59°C/m

m = molality of solution = 0.0312 m

Putting values in above equation, we get:

$16.6^oC-\text{freezing point of solution}=1\times 3.59^oC/m\times 0.0312m\\\\\text{Freezing point of solution}=16.5^oC$

Hence, the freezing point of solution is 16.5°C

Calculation for boiling point of solution:

Elevation in boiling point is defined as the difference in the boiling point of solution and freezing point of pure solution.

The equation used to calculate elevation in boiling point follows:

$\Delta T_b=\text{Boiling point of solution}-\text{Boiling point of acetic acid}$

To calculate the elevation in boiling point, we use the equation:

$\Delta T_b=iK_bm$

or,

$\text{Boiling point of solution}-\text{Boiling point of acetic acid}=iK_fm$

where,

Boiling point of acetic acid = 118.1°C

i = Vant hoff factor = 1 (for non-electrolyte)

$K_f$ = molal boiling point elevation constant = 3.08°C/m

m = molality of solution = 0.0312 m

Putting values in above equation, we get:

$\text{Boiling point of solution}-118.1^oC=1\times 3.08^oC/m\times 0.0312m\\\\\text{Boiling point of solution}=118.2^oC$

Hence, the boiling point of solution is 118.2°C

5 0

3 years ago

Which consequence of global warming is described as having an increase in growing season changes in migration and loss of specie

IgorLugansk [536]

Answer:

Deforestation, increase wildlife extinction, ecosystem imbalances, soil erosion, migration and loss of species.

Explanation:

Global warming is warming the earth's surface temperature, which causes the changes in our ecosystem like deforestation, soil erosion, climate changes, migration and loss of species etc.

Global warming is caused by the 'Greenhouse effect', major gases are carbon dioxide(9-26%), methane(4-9%), water vapour(36-70%) ozone(3-7%) and nitrous oxide.

Global warming affects on the ocean include rising sea level, meiting glaciers, thermal expansion and ice sheets. It also cause the bird migration which carries high cost of predation and mortality.

8 0

4 years ago

Read 2 more answers

Describe how the meniscus is used to read volume measurements on a graduated cylinder

katrin2010 [14]

Answer:Tthe liquid in a graduated cylinder curves up at the edge where the liquid meets the wall of the cylinder. This curve in the liquid is called the meniscus and is used to determiine the volume of liquid in a graduated cylinder by observing the measurement tick closest to the bottom of the meniscus.

Explanation:

Hope it helps :D

4 0

2 years ago

Read 2 more answers

What does volcanic ash add to the environment?

Travka [436]

Somethings that are beneficial is its good for plants, if it is very fine ash it is able to break down and quickly dissolve into the soil.

7 0

3 years ago