What is the percent by mass of oxygen in al2o3 ?

1. Marisa determined the melting point of a substance to be 24.5C. Find the percent error of her measurement if the actual melti

USPshnik [31]

Answer:

$\%\ Error = 21.5\%$

Explanation:

Given

$Measured = 24.5$

$Actual = 31.2$

Required

Determine the percentage error

First, we need to determine the difference in the measurement

$Difference = |Actual - Measured|$

$Difference = |31.2 - 24.5|$

$Difference = |6.7|$

$Difference = 6.7$

The percentage error is calculated as thus:

$\%\ Error = \frac{Difference * 100\%}{Actual}$

$\%\ Error = \frac{6.7 * 100\%}{31.2}$

$\%\ Error = \frac{670\%}{31.2}$

$\%\ Error = 21.4743589744\%$

$\%\ Error = 21.5\%$ approximated

6 0

3 years ago

Some versions of the periodic table show hydrogen at the top of Group 1A(1) and at the top of Group 7A(17). What properties of h

lawyer [7]

Answer:Hydrogen is placed such because it exhibits some similar characteristics of both group1 and group VII elements.

Explanation:

The reason why hydrogen is similar to group 1 metals:

#It has same valence electron and inorder achieve octet state it can lose that electron and forms H+ ion

#It acts as a good reducing agent similar to group1 metals

#It can also halides

Similarity to halogens:

#hydrogen can also gain one electron to gain noble gas configuration. It can combine with other non metals to form molecules with covalent bonding.

#It exists as diatomin molecule,H2

#Have the same electronegativity nature

#its reaction with other metal

8 0

3 years ago

How are carrot, an amoeba, and a bacterium alike

sineoko [7]

They should all be eukaryotic.

4 0

3 years ago

Read 2 more answers

Methyl salicylate is a common active ingredient in liniments such as ben-gay. It is also known as oil of wintergreen. It is made

arlik [135]

Answer: The empirical formula is $C_3H_3O$ .

Explanation:

The chemical equation for the combustion of hydrocarbon having carbon, hydrogen and oxygen follows:

$C_xH_yO_z+O_2\rightarrow CO_2+H_2O$

where, 'x', 'y' and 'z' are the subscripts of Carbon, hydrogen and oxygen respectively.

We are given:

Mass of $CO_2$ = 12.24 g

Mass of $H_2O$ = 2.505 g

Molar mass of carbon dioxide = 44 g/mol

Molar mass of water = 18 g/mol

For calculating the mass of carbon:

In 44g of carbon dioxide, 12 g of carbon is contained.

So, in 12.24 g of carbon dioxide, = $\frac{12}{44}\times 12.24=3.338g$ of carbon will be contained.

For calculating the mass of hydrogen:

In 18g of water, 2 g of hydrogen is contained.

So, in 2.505 g of water, = $\frac{2}{18}\times 2.505=0.278g$ of hydrogen will be contained.

Mass of oxygen in the compound = (5.287) - (3.338+0.278) = 1.671 g

Step 1 : convert given masses into moles.

Moles of C = $\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{3.338g}{12g/mole}=0.278moles$

Moles of H= $\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{0.278g}{1g/mole}=0.278moles$

Moles of O= $\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{1.671g}{16g/mole}=0.104moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C = $\frac{0.278}{0.104}=3$

For H = $\frac{0.278}{0.104}=3$

For O = $\frac{0.104}{0.104}=1$

The ratio of C : H : O = 3: 3: 1

Hence the empirical formula is $C_3H_3O$ .

5 0

3 years ago

Before applying the corkscrew, Lucas discovers a bit of mold on the cork of a bottle of Pinot Noir. Lucas should A. ignore the m

Alenkinab [10]

The question says,'before applying the corkscrew, Lucas discovers a bit of mold on the cork of a bottle of Pinot Noir. Lucas should............. The correct option is B. The standard method of removing mold from wine cork is to dampen a clean napkin with water and use it to wipe the mold away from the cork. The cork should then be removed and the outside and the inside of the wine neck must be cleaned thoroughly as well.

3 0

2 years ago