All categories

3 years ago

HELP PLEASE!!! I AM BEING TIMED! I WILL GIVE YOU BRAINLIEST!!

Chemistry

1 answer:

r-ruslan [8.4K]3 years ago

3 0

Answer:

Explanation:

I HOPE IT HELPS :)

You might be interested in

The half-life of cobalt-60 is 5.3 years. after __________ years, 1/4 of the original amount of cobalt-60 will remain.

cestrela7 [59]

The number of years required for 1/4 cobalt-60 to remain after decay is calculated as follows

after one half life 1/2 of the original mass isotope remains

after another half life 1/4 mass of original mass remains

therefore if one half life is 5.3 years then the years required

= 2 x 5.3years = 10.6 years

4 0

3 years ago

Read 2 more answers

In acidic aqueous solution, the purple complex ion Co(NH3)5Br2+ undergoes a slow reaction in which the bromide ion is replaced b

kirill115 [55]

Answer:

A) 0.065 M is its molarity after a reaction time of 19.0 hour.

B) In 52 hours $[Co(NH_3)5Br]^{2+}$ will react 69% of its initial concentration.

Explanation:

$Co(NH_3)_5(H_2O)_3+[Co(NH_3)5Br]^{2+}(Purple)(aq)+H_2O(l)\rightarrow [Co(NH_3)_5(H_2O)]^{3+}(Pinkish-orange)(aq)+Br^-(aq)$

The reaction is first order in $[Co(NH_3)5Br]^{2+}$ :

Initial concentration of $[Co(NH_3)5Br]^{2+}$ = $[A_o]=0.100 M$

a) Final concentration of $[Co(NH_3)5Br]^{2+}$ after 19.0 hours= $[A]$

t = 19.0 hour = 19.0 × 3600 seconds ( 1 hour = 3600 seconds)

Rate constant of the reaction = k = $6.3\times 10^{-6} s^{-1}$

The integrated law of first order kinetic is given as:

$[A]=[A_o]\times e^{-kt}$

$[A]=0.100 M\times e^{-6.3\times 10^{-6} s^{-1}\times 19.0\times 3600 s}$

$[A]=0.065 M$

0.065 M is its molarity after a reaction time of 19.0 h.

Initial concentration of $[Co(NH_3)5Br]^{2+}$ = $[A_o]=x$

Final concentration of $[Co(NH_3)5Br]^{2+}$ after t = $[A]=(100\%-69\%) x=31\%x=0.31x$

Rate constant of the reaction = k = $6.3\times 10^{-6} s^{-1}$

The integrated law of first order kinetic is given as:

$[A]=[A_o]\times e^{-kt}$

$0.31x=x\times e^{-6.3\times 10^{-6} s^{-1}\t}$

t = 185,902.06 s = $\frac{185,902.06 }{3600} hour = 51.64 hours$ ≈ 52 hours

In 52 hours $[Co(NH_3)5Br]^{2+}$ will react 69% of its initial concentration.

6 0

4 years ago

A gas has a density of 1.57 g/L at 40.0 Â°C and 2.00 atm of pressure. What is the identity of the gas?

Naddika [18.5K]

Answer:

Neon

Explanation:

Step 1: Given and required data

Density of the gas (ρ): 1.57 g/L

Temperature (T): 40.0°C

Pressure (P): 2.00 atm

Ideal gas constant (R): 0.08206 atm.L/mol.K

Step 2: Convert T to Kelvin

We will use the following expression.

K = °C + 273.15 = 40.0 + 273.15 = 313.2 K

Step 3: Calculate the molar mass of the gas (M)

For an ideal gas, we will use the following expression.

ρ = P × M/R × T

M = ρ × R × T/P

M = 1.57 g/L × 0.08206 atm.L/mol.K × 313.2 K/2.00 atm

M = 20.17 g/mol

The gas with a molar mass of 20.17 g/mol is Neon.

6 0

3 years ago

Briefly discuss the 3 most important properties of metals

Elan Coil [88]

Answer: Luster: Metals are shiny when cut, scratched, or polished.

Malleability: Metals are strong but malleable, which means that they can be easily bent or shaped.

Conductivity: Metals are excellent conductors of electricity and heat.

Explanation: Hope this helped!

7 0

2 years ago

How many protons, electrons, and neutrons does an atom with atomic number

sergey [27]

Answer:

protons : 10

electron : 10

neutron : 10

Explanation:

Protons will usually be the same as the electrons when its a <u>Atom</u> (when its a ion or covalent bond or simple bond they will most likely be different)

the atomic number represents protons and electrons

the mass number - the atomic number = neutron

8 0

3 years ago