Round off 00907506 to four significant figures.

What is the formula mass of the fictitious compound: AB2?

Rus_ich [418]

For a molecule AB2, 3.5g of A represents one molar fraction, and 8.00g B represents 2 molar fractions (or 4.0+4.0). Therefore, a direct ratio can be given as 3.5:4.0, or 1:1.14. This means a molecule AnBm will give a mass ratio for A:B of n:1.14xm

For a molecule AB, for every 1g of A, you will have 1.14g of B.

For a molecule AB2, for every 1g of A, you will have 2.28g of B.

For a molecule A2B3, for every 1g of A, you will have (1.14x3/2) 1.71g of B.

3 0

3 years ago

For the following reaction, 4.34 grams of sulfur dioxide are mixed with excess oxygen gas . The reaction yields 3.89 grams of su

Degger [83]

Answer:

5.42g, 71.77%

Explanation:

First, we have to write out the balanced chemical equation. The unbalanced equation can be written as “SO2+O2 -> SO3” and to balance it, we can see that having two mols of SO2 and two mols of SO3 will make each side have the same amount of mols per element on each side. So the balanced chemical equation is “2SO2 + O2 -> 2SO3”

Now, we want to solve for the theoretical yield in grams of SO3. To do this, we have to use dimensional analysis. We convert g SO2 into mols SO2 using the molar mass of the elements. Then we convert mols of SO2 into mols of SO3 using the balanced equation. Once we’ve done that, we can convert mols of SO3 into grams of SO3.

You should know how to look up the molar mass of elements on the periodic table by now. Find the masses and set up the terms so they cancel like so:

$4.34g \times \frac{1mol \: so2}{64.07g \: so2} \times \frac{2 \: mol \: so3}{2 \: mol \: so2} \times \frac{80.07gso3}{1 \: mol \: so3}$

Doing the math, we get 5.42g so3 as the theoretical yield. This is the most amount that you could ever get if the world was a perfect place. But alas, it isn’t and mistakes are gonna happen, so the number is going to be less than that. So the best we can do, is to figure out the percent yield that we got.

In a lab scenario, this was calculated to be 3.89 g as stated by the problem. The percent composition formula is

$| \frac{result}{expected \: result} | \times 100$

and plugging the numbers into it, we get:

$| \frac{3.89}{5.42} | \times 100 = 71.77\%$

make sure to follow the decimal/significant figure rules of your instructor, but only round at the end. My professor didn't care too much thankfully, but some professors do

6 0

2 years ago

An unknown insoluble substance displaced the water shown. It's mass is indicated on the triple beam balance. Mass = A. 694 B. 69

vodka [1.7K]

Answer:

D. 693.8.

Explanation:

The first scale of the triple beam balance indicate that the mass is 600.

The second scale of the triple beam balance indicate that the mass is 690.

The third scale of the triple beam balance indicate that the mass is higher that 693.5 and the scale is near but lower than 694, so the mass = 693.8.c

3 0

3 years ago

Read 2 more answers

ANSWER QUICK PLEASE <br> WORTH 100 POINTS

sukhopar [10]

Answer:

Explanation:

Volume is defined as the space occupied by an object or substance irrespective of its state of matter.The conversion used from millimeter to liter is:

1 milliiliter = 0.001 L

Therefore, we can convert the volume of sample from 2.5 ml in liters as follows.

2.5 ml in liters = 2.5ml x 0.001 L/1ml

= 0.0025 L

Thus, we can conclude that the volume of given sample in liter is 0.0025 L

Hope this helps! :)

6 0

3 years ago

1. The forks shown are made of silver (Ag). Some of the silver forks

Anon25 [30]

Answer:

Corrosion

Explanation:

Silver, although known as a nobble metal, is also subject to corrosion process such as having silver tarnish when exposed to sulfur and air.

Tarnishing occurs on the surfaces of some metals such as brass, copper, and silver, which results in a corroded layer. Silver tarnish occurs from the chemical reaction that takes place when silver is exposed to sulfur which results in the formation of black Ag₂S

In order to restore the original silver surface, the silver tarnish (silver sulfide) layer is removed.

We have the statement presented here as follows;

The forks shown are made of silver (Ag). Some of the silver forks shown have lost their luster - they have become tarnished. This is an example of <u>Corrosion.</u>

4 0

3 years ago