All categories

3 years ago

What is the function of tunnels and passageways in subsurface mining?

1 answer:

5 0

The answer is D because they would have to make quarries just below the surface to mine
Mineral ores much quicker (Quarries- a large hole/pit under ground used to get stone and minerals)

You might be interested in

Using the Bohr model, determine the energy, in joules, necessary to ionize a ground-state hydrogen atom. Show your calculations.

lord [1]

Answer:

The energy required to ionize the ground-state hydrogen atom is 2.18 x 10^-18 J or 13.6 eV.

Explanation:

To find the energy required to ionize ground-state hydrogen atom first we calculate the wavelength of photon required for this operation.

It is given by Bohr's Theory as:

1/λ = Rh (1/n1² - 1/n2²)

where,

λ = wavelength of photon

n1 = initial state = 1 (ground-state of hydrogen)

n2 = final state = ∞ (since, electron goes far away from atom after ionization)

Rh = Rhydberg's Constant = 1.097 x 10^7 /m

Therefore,

1/λ = (1.097 x 10^7 /m)(1/1² - 1/∞²)

λ = 9.115 x 10^-8 m = 91.15 nm

Now, for energy (E) we know that:

E = hc/λ

where,

h = Plank's Constant = 6.625 x 10^-34 J.s

c = speed of light = 3 x 10^8 m/s

Therefore,

E = (6.625 x 10^-34 J.s)(3 x 10^8 m/s)/(9.115 x 10^-8 m)

E = 2.18 x 10^-18 J

E = (2.18 x 10^-18 J)(1 eV/1.6 x 10^-19 J)

E = 13.6 eV

5 0

4 years ago

how is the ammonium ion (NH4)1- and the oxalate ion (C2O4) 2- combine written in the ionic compound formed?

lana66690 [7]

Answer: Shown In Photo

Explanation:

just crisscross as shown in photo good luck i suck @ explaining

4 0

3 years ago

Please help with word equations?

Delvig [45]

For the answer to the questions above,

a) Ag2CO3(s) => Ag2O(s)+CO2(g)

b) Cl2(g)+2(KI)(aq) => I2(s)+2(KCl)(aq) (coefficients are for balanced equation) 
net ionic is Cl2(g)+2I- => I2(s)+2Cl-(aq) 

c) I2(s)+3(Cl2)(g)=>2(ICl3)
I hope I helped you with your problem

7 0

4 years ago

Which one of the following pairs of acids and conjugate bases is incorrectly labeled or incorrectly matched? Acid Conjugate Base

vekshin1

Answer : The incorrect option is, (d) $NH_4^+/NH_2^-$

Explanation :

According to the Bronsted Lowry concept, Bronsted Lowry-acid is a substance that donates one or more hydrogen ion in a reaction and Bronsted Lowry-base is a substance that accepts one or more hydrogen ion in a reaction.

Or we can say that, conjugate acid is proton donor and conjugate base is proton acceptor.

(a) The equilibrium reaction will be,

$HF+H_2O\rightleftharpoons F^-+H_3O^+$

In this reaction, $HF$ is an acid that donate a proton or hydrogen to $H_2O$ base and it forms $F^-$ and $H_3O^+$ are conjugate base and acid respectively.

In this reaction, $HF/F^-$ are act as a conjugate acid-base.

(b) The equilibrium reaction will be,

$HClO+H_2O\rightleftharpoons ClO^-+H_3O^+$

In this reaction, $HClO$ is an acid that donate a proton or hydrogen to $H_2O$ base and it forms $ClO^-$ and $H_3O^+$ are conjugate base and acid respectively.

In this reaction, $HClO/ClO^-$ are act as a conjugate acid-base.

(c) The equilibrium reaction will be,

$H_2O+H_2O\rightleftharpoons OH^-+H_3O^+$

In this reaction, $H_2O$ is an acid that donate a proton or hydrogen to

In this reaction, $H_2O/OH^-$ are act as a conjugate acid-base.

(d) The equilibrium reaction will be,

$NH_4^++H_2O\rightleftharpoons NH_3+H_3O^+$

In this reaction, $NH_4^+$ is an acid that donate a proton or hydrogen to $H_2O$ base and it forms $NH_3$ and $H_3O^+$ are conjugate base and acid respectively.

In this reaction, $NH_4^+/NH_3$ are act as a conjugate acid-base.

(e) The equilibrium reaction will be,

$H_3O^++H_2O\rightleftharpoons H_2O+H_3O^+$

In this reaction, $H_3O^+$ is an acid that donate a proton or hydrogen to $H_2O$ base and it forms

In this reaction, $H_3O^+/H_2O$ are act as a conjugate acid-base.

From this we conclude that that, $NH_4^+/NH_2^-$ pairs of acids and conjugate bases is incorrectly labeled or incorrectly matched.

Hence, the incorrect option is, (d) $NH_4^+/NH_2^-$

4 0

3 years ago

The equilibrium constant for the chemical equation N2(g) + 3H2(g) ⇌ 2NH3(g) and Kp=0.174 at 243°C. Calculate the value of Kc for

Mashcka [7]

Answer:

The Kc of this reaction is 311.97

Explanation:

Step 1: Data given

Kp = 0.174

Temperature = 243 °C

Step 2: The balanced equation

N2(g) + 3H2(g) ⇌ 2NH3(g)

Step 3: Calculate Kc

Kp = Kc *(RT)^Δn

⇒ with Kp = 0.174

⇒ with Kc = TO BE DETERMINED

⇒ with R = the gas constant = 0.08206 Latm/Kmol

⇒ with T = the temperature = 243 °C = 516 K

⇒ with Δn = number of moles products - moles reactants 2 – (1 + 3) = -2

0.174 = Kc (0.08206*516)^-2

Kc = 311.97

The Kc of this reaction is 311.97

3 0

3 years ago