The equation that represents

The decomposition of a compound at 400⁰C is first order with half-life of 1570 seconds. what fraction of an initial amount of th

kirill115 [55]

Answer: After 4710 seconds, 1/8 of the compound will be left

Explanation:

Using the formulae

Nt/No = (1/2)^t/t1/2

Where

N= amount of the compound present at time t

No= amount of compound present at time t=0

t= time taken for N molecules of the compound to remain = 4710 seconds

t1/2 = half-life of compound = 1570 seconds

Plugging in the values, we have

Nt/No = (1/2)^(4710s/1570s)

Nt/No = (1/2)^3

Nt/No= 1/8

Therefore after 4710 seconds, 1/8 molecules of the compound will be left

5 0

2 years ago

Calculate the vapor pressure in torr of a solution containng 24.5 g of glycerin (C3H8O3) in 135 mL water at 30.0* C; the vapor p

Otrada [13]

Psolution = X · PH_20
= 0.966 · 31.8 torr
= 30.7 torr

3 0

2 years ago

I'm stuck on this assignment, +20 PTS and BRAINLIEST for step by step:

dolphi86 [110]

Answer:

2. 2.74 L

3. 488 K

4. 7.47 L

5. 38.6 L

6. 2.85 mol

7. 319 K

8. 3.43 kPa

Explanation:

Generally speaking, you want to convert units to SI units, but in this case, we are working with ratios. This makes up for using the units that wouldn't appropriate elsewhere.

2. Use the equation P₁V₁ = P₂V₂. Solve for V₂.

(3.05 L)(870 kPa) = (969 kPa)(V₂)

V₂ = 2.74 L.

3. Use the equation V₁/T₁ = V₂/T₂. Solve for T₂.

(3.32 L)/(360 K) = (4.50 L)/(T₂)

T₂ = 488 K.

4. Do the same as above, but for V₂.

(5.10 L)/(-56°C) = V₂/(-82°C)

V₂ = 7.47 L

5. Use the equation V₁/n₁ = V₂/n₂. Solve for V₂.

(37.2 L)/(0.750 mol) = (V₂)/(0.778 mol)

V₂ = 38.6 L

6. Do the same as above, but for n₂.

(86.0 L)/(2.65 mol) = (92.5 L)(n₂)

n₂ = 2.85 mol

7. Use the equation P₁/T₁ = P₂/T₂. Solve for T₂.

(3.00 atm)/(390 K) = (2.45 atm)/(T₂)

T₂ = 319 K

8. Do the same as above, but for P₂.

In this specific case, however you will need to convert units. Since both temperatures don't have the same sign, the ratio won't come out right. Convert to Kelvin. Add 273.15 to the temperature in Celsius to convert to Kelvin -12.3°C = 260.85 K 25°C = 298.15 K.

(3.00 kPa)/(260.85 K) = P₂/(298.15 K)

P₂ = 3.43 kPa

There is a lot in here... If you are confused about something, let me know!

6 0

3 years ago

Relate the properties of atoms, their position in the periodic table, and their number of valence electrons to their chemical re

dalvyx [7]

Answer:

Explanation:

An atom is the smallest unit of an element that can take part in a chemical reaction. Atoms are made up of protons, neutrons and electrons. Atoms can exist as a monoatomic (such as in the case of Helium, Xenon and Neon) or as diatomic (such as in the case of oxygen and nitrogen). Atoms take part in a chemical reaction and there reactivity varies among themselves.

From the above, it can be deduced that atoms have protons, neutrons and electrons. The number of protons (which is positively charged) of an atom determines it's position on the periodic table because elements in the periodic table are arranged according to the number of protons (called atomic number). The electron(s) present in the outermost shell of each atom (called valence electrons) determines there chemical reactivity. What happens here is that, all atoms (except noble gases) want to achieve there duplet or octet configuration so as to become stable. This octet configuration means they want to have there outermost shell completely filled (with eight electrons or two electrons for duplet). They usually achieve this configuration by taking part in chemical reactions. Thus, when an atom has just one electron in it's outermost shell, it becomes easy to lose it to another atom by way of interacting with it in a chemical reaction. When it loses this single electron (valence electron) in it's outermost shell, it becomes stable with the inner completely filled shell (that would be the new outermost shell). Examples include Lithium, sodium and potassium. Sodium (with eleven electrons and three shells) would lose the single electron in it's outermost shell so as to have just two shells with the second shell completely filled with eight electrons. Thus, the more the valence electron to be lost to achieve the octet structure, the lesser the reactivity of the atom.

Also, an atom that has just one electron to complete it's own outermost shell and thus achieve it's octet structure is also highly reactive. This is also because it is easy for this atom to receive a single electron and become completely filled. Examples include chlorine, fluorine and iodine. Fluorine (with nine electrons and two shells) will easily accept one more electron so as to achieve it's octet structure with a completely filled outermost shell (of eight electrons). Thus, the lesser the electrons to be gained to achieve the octet configuration, the higher the chemical reactivity of such atoms. Noble gases have extremely low or no reactivity at all for this reason because it has a completely filled outermost shell (no losing or donating).

It should also be noted that metals (which are found on the left of the periodic table) exist as monoatomic while gases (which are found on the right), with the exception of noble gases, are mostly diatomic.

3 0

2 years ago

select the equations that are correctly balanced. h2o 2o2? h2o2 fe2o3 3h2? 2fe 3h2o al 3br2? albr3 caco3? cao co2 can you clarif

natta225 [31]

The choices are as follows:
h2o + 2o2 = h2o2
fe2o3 + 3h2 = 2fe + 3h2o
al + 3br2 = albr3
caco3 = cao + co2

The correct answers would be the second and the last option. The equations that are correctly balanced are:

 fe2o3 + 3h2 = 2fe + 3h2o
caco3 = cao + co2

To balance, it should be that the number of atoms of each element in the reactant and the product side is equal.

8 0

2 years ago