Element (20X) in the periodic table exist in:

Identify whether each reaction represents a chemical reaction or a nuclear reaction by filling in the blank with the word ‘chemi

valkas [14]

A chemical reaction is defined as the reaction between two or more substances that produces new substances/compounds.

On the other hand, a nuclear reaction is a reaction that alters the nucleus of a certain atom. This can be done either by splitting the nucleus or by joining this nucleus with another one.

Reaction 1:
Cl₂ + H₂ ............> 2 HCl
This is the combination of two elements to produce a new compound.
Therefore, this reaction is a chemical reaction

Reaction 2:
²₁H + ³₁H .........> ⁴₂H + ¹₀n
This is an alteration in the nucleus of a hydrogen atom by bonding it with another nucleus.
Therefore, this reaction is a nuclear reaction

Hope this helps :)

5 0

2 years ago

Read 2 more answers

How many grams of Na2CO3 must be dissolved into 155g of water to create a solution with a molarity of 8.20 mol/kg

zhannawk [14.2K]

Answer:

135g Na2CO3

Explanation:

I'm going to assume you mean Molality which is mol solute/kg solvent

Molarity would be mol soute/ L solution

we know we have 155g of water which is .155 kg

essentially we have the equation:

mol/kg = 8.20

we substitute .155 in for kg and get:

mol/.155 = 8.20

Solving this gives mol = 1.271

now we must convert to grams using the molar mass

Molar mass Na2CO3 = 106G/mol

so to cancel moles we multiply:

1.271mol x 106g/mol

= 135g

4 0

2 years ago

This decomposition is first order with respect to phosphine, and has a half‑life of 35.0 s at 953 K. Calculate the partial press

Solnce55 [7]

Answer:

0.57 atm

Explanation:

When a a reaction is first order, we have from calculus the following relation:

ln[A]t/[A]₀ = - kt

where [A]t is the concentration of A ( phosphine in this case ) after a time, t

[A]₀ is the initial concentration of A

k is the rate constant, and

t is the time

We also know that for a first order reaction

k = 0.693/ t 1/2

wnere t 1/2 is the half-life.

This equation is derived for the case when A]t/= 1/2 x [A]₀ which occurs at the half-life.

Thus, lets first find k from the half life time, and then solve for t = 70.5 s

k = 0.693 / 35.0 s = 0.0198 s⁻¹

ln [ PH₃ ]t / [ PH₃]₀ = - kt

from the ideal gas law we know pV = nRT, so the volumes cancel:

ln (pPH₃ )t / p(PH₃)₀ = - kt

taking inverse log to both sides of the equation:

(pPH₃ )t / p(PH₃)₀ = - kt

thus:

(pPH₃ )t = 2.29 atm x e^(- 0.0198 s⁻¹ x 70.5 s ) = 0.57 atm

3 0

3 years ago

Consider an amphoteric hydroxide, m(oh)2(s), where m is a generic metal. estimate the solubility of m(oh)2 in a solution buffere

Colt1911 [192]

Missing data in your question: (please check the attached photo)
from this balanced equation:
M(OH)2(s) ↔ M2+(aq) + 2OH-(aq) and when we have Ksp = 2x10^-16
∴Ksp = [M2+][OH]^2
2x10^-16 = [M2+][OH]^2
a) SO at PH = 7
∴POH = 14-PH = 14- 7 = 7
when POH = -㏒[OH]
7= -㏒[OH]
∴[OH] = 1x10^-7 m by substitution with this value in the Ksp formula,
∴[M2+] =Ksp /[OH]^2
= (2x10^-16)/(1x10^-7)^2
= 0.02 M
b) at PH =10
when POH = 14- PH = 14-10 = 4
when POH = -㏒[OH-]
    4 = -㏒[OH-]
∴[OH] = 1x10^-4 ,by substitution with this value in the Ksp formula
[M2+] = Ksp/ [OH]^2
= 2x10^-16 / (1x10^-4)^2
  = 2x10^-8 M
c) at PH= 14
when POH = 14-PH
= 14 - 14
= 0
when POH = -㏒[OH]
  0 = - ㏒[OH]
∴[OH] = 1 m
by substitution with this value in Ksp formula :
[M2+] = Ksp / [OH]^2
= (2x10^-16) / 1^2
= 2x10^-16 M

8 0

3 years ago

Water will boil at 50°C if the pressure on the<br> surface of the water is

Pachacha [2.7K]

Water boils when its vapor pressure equals the prevailing atmospheric pressure over the water. In order for water to boil at 50 ºC, the pressure over the water would need to be reduced to a point greater equal to the vapor pressure of the water (92.5 torr).

8 0

3 years ago