All categories

4 years ago

Please help! I need answers please!

Chemistry

1 answer:

eduard4 years ago

3 0

2. B: aluminum

3. D: Scientists could not agree on a standard.

4.B: Nonmetals

You might be interested in

Please help me this is my fourth attempt.

Vaselesa [24]

Explanation:

CH4 + 4S ---> CS2 + 2H2S

4) 0.75 mol S × (1 mol CS2/4 mol S) = 0.19 mol CS2

5) 3 mol H2S × (1 mol CH4/2 mol H2S) = 1.5 mol CH4

Fe2O3 + 2Al ---> 2Fe + Al2O3

6) 25 g FeO3 × (1 mol Fe2O3/159.69 g Fe2O3) = 0.16 mol Fe2O3

0.16 mol Fe2O3 × (2 mol Al/1 mol Fe2O3) = 0.32 mol Al

0.32 mol Al × (26.98 g Al/1 mol Al) = 8.6 g Al

7) Given:

45 g Al × (1 mol Al/26.98 g Al) = 1.6 mol Al

85 g Fe2O3 ×(1 mol Fe2O3/159.69 g Fe2O3)

= 0.53 mol Fe2O3

Let's look at how much Fe each reactant will produce:

1.6 mol Al × (2 mol Fe/2 mol Al) = 1.6 mol Fe

0.53 mol Fe2O3 × (2 mol Fe/1 mol Fe2O3) = 1.1 mol Fe

Note that the given amount of Fe2O3 will give us fewer Fe. Therefore, Fe2O3 is the limiting reactant.

8) Al will produce 1.6 mol Fe × (55.845 g Fe/1 mol Fe)

= 89 g Fe

Fe2O3 will produce 1.1 mol Fe × (55.845 Fr/1 mol Fe)

= 61 g Fe

9) Since Fe2O3 is the limiting reactant, the ideal yield of Fe for the reaction is 61 g. If the actual reaction only gave us 25 g Fe. then the percent yield of Fe is

%yield = (25 g Fe/61 g Fe) × 100% = 41%

10) If we only got 25 g Fe, then the amount of Al actually used in the reaction is

25 g Fe × (1 mol Fe/55.845 g Fe) = 0.45 mol Fe

0.45 mol Fe × (2 mol Al/2 mol Fe) = 0.45 mol Al

0.45 mol Al × (26.98 g Al/1 mol Al) = 12 g

Therefore, the leftover amount of Al is

25 g Al - 12 g Al = 13 g Al

8 0

3 years ago

A large marble is dropped in a graduate cylinder with 35ml of water in it .The water level increases to 49ml.what is the volume

PilotLPTM [1.2K]

The volume of the marble is 14ml

6 0

3 years ago

Read 2 more answers

How many kilocalories of heat are released when 75 g of steam at 100 degrees Celsius is converted to ice at 0 degrees Celsius?

VikaD [51]

Answer:

∴ Q = -7.52kCal

Explanation:

Using the formula for specific heat capacity:

Q = mcΔT

where ΔT = change in temperature (final - initial) = (0 - 100)°C = -100°C

m = mass (g) = 75g

c = specific heat capacity = 4.2 J/g°C in water

⇒ Q = 75 × 4.2 × -100

= -31,500J

But 1J - 0.000239kCal

∴ Q = -7.52kCal

Let me know if I can be of further assistance.

5 0

3 years ago

Vitamin c is known chemically by the name ascorbic acid determine the empirical formula of ascorbic acid if it is composed of 40

kow [346]

Answer:

$=C_3H_4O_3$

Explanation:

When percentage composition is given, and asked for the empirical formula, it is simplest to assume 100 g of material. Thus,

Mass C = 40.92 g. Moles C = 40.92 g x 1 mole/12 g = 3.41 moles C

Mass H = 4.58 g. Moles H = 4.58 g x 1 mole/1.0 g = 4.58 moles H

Mass O = 54.50 g. Moles O = 54.50 g x 1 mole/16 g = 3.41 moles O

Now, we want to get the moles into whole numbers, so we begin by dividing all by the smallest, i.e. divide all values by 3.41.

Moles C = 3.41/3.41 = 1

Moles H = 4.58/3.41 = 1.34

Moles O = 3.41/3.41 = 1

Now, in order to get 1.34 to be a whole number we multiply it (and all others) by 3

Moles C = 1x3 = 3

Moles H = 1.34x3 = 4

Moles O = 1x3 = 3

Empirical Formula $=C_3H_4O_3$

3 0

3 years ago

which of the following chemical symbol is that of an element with six electrons in the outermost shell a)Ca b)Cl c)Ne d)S

nydimaria [60]

Hey there!

Sulphur is the element which has 6 electrons in the outermost shell.

WhereasCalcium,Neon have 2 and chlorine has 7.

Hope this explanation helps you :)
Have a good day :)

5 0

2 years ago

Read 2 more answers