Element whose atoms have completed their outer energy level are the ___

Which symbol can be used to indicate the pressure at which a chemical reaction is carried out? 25 degrees Celsius over a right a

jolli1 [7]

Answer:

2 atm

Explanation:

Chemical reactions are carried out at a certain rate. Sometimes that rate is quite slow, so we want to speed things up, which is usually used by increasing temperature, increasing pressure or adding a catalyst (a substance that increases the rate without changing itself).

If this is the case, then, when writing a chemical equation, we state these special conditions over a right arrow.

Now let's look at the answers:

- 25°C is a value and unit of temperature

- ∆ is a symbol that denotes change

- 2 atm is a value and unit of pressure (atmosphere is old unit for pressure)

- Pt is a chemical symbol for platinum, an element often used as a catalyst.

So, the correct answer is C) 2 atm

7 0

3 years ago

Read 2 more answers

When N2(g) reacts with H2(g) to form NH3(g), 92.2 kJ of energy are evolved for each mole of N2(g) that reacts. Write a balanced

Naddika [18.5K]

Answer:

N₂ + 3H₂ → 2NH₃ ΔH = - 92.2KJ

Explanation:

Let's write out the chemical equation between Nitrogen and Hydrogen to Form Ammonia.

Nitrogen + Hydrogen = Ammonia

N₂ + H₂ → NH₃

A Thermochemical Equation is a balanced stoichiometric chemical equation that includes the enthalpy change, ΔH.

The balanced stoichiometric chemical equation is given as;

N₂ + 3H₂ → 2NH₃

92.2 kJ of energy are evolved for each mole of N2(g) that reacts. And from the equation, 1 mole of N2 reacts.

The enthalpy change, ΔH = - 92.2KJ. The negative sign is because heat is being evolved.

The balanced thermochemical equation;

N₂ + 3H₂ → 2NH₃ ΔH = - 92.2KJ

6 0

3 years ago

Two objects of the same mass are moving at the same velocity. You give

vladimir1956 [14]

I would imagine they’d be equal.
F = ma
We can treat mass and force as constants because they do not change throughout both systems and they are the same on both systems. That would mean the acceleration would be the same for both systems.

An explanation of this could be the two forces are acting in different directions, so one is positively accelerating the object and the other is negatively accelerating it

3 0

3 years ago

A 25.0g sample of brass, which has a specific heat capacity of 0.375·J·g−1°C−1, is dropped into an insulated container containin

Angelina_Jolie [31]

Answer:

The equilibrium temperature of water is 25.6 °C

Explanation:

Step 1: Data given

Mass of the sample of brass = 25.0 grams

The specific heat capacity = 0.375 J/g°C

Mass of water = 250.0 grams

Temperature of water = 25.0 °C

The initial temperature of the brass is 96.7°C

Step 2: Calculate the equilibrium temperature

Heat lost = heat gained

Q(sample) = -Q(water)

Q = m*C* ΔT

m(sample)*c(sample)*ΔT(sample) = - m(water)*c(water)*ΔT(water)

⇒m(sample) = the mass of the sample of brass = 25.0 grams

⇒with c(sample) =The specific heat capacity = 0.375 J/g°C

⇒with ΔT = the change of temperature = T2 - T1 =T2 - 96.7 °C

⇒with m(water) = the mass of the water = 250.0 grams

⇒with c(water) = the specific heat capacity = 4.184 J/g°C

⇒with ΔT(water) = the change of temperature of water = T2 - T1 = T2 - 25.0°C

25.0 * 0.375 * (T2 - 96.7) = - 250.0 * 4.184 J/g°C * (T2 - 25.0°C)

9.375T2 - 906.56 = -1046T2 + 26150

9.375T2 + 1046T2 = 26150 + 906.56

1055.375T2 = 27056.26

T2 = 25.6 °C

The equilibrium temperature of water is 25.6 °C

4 0

3 years ago

What is the angle between two of the nitrogen-hydrogen bonds in the ammonium (NH4+) ion?

Arlecino [84]

Answer:

109° 27'

Explanation:

The ammonium ion is tetrahedral in shape, all the HNH bonds are exactly at the tetrahedral bond angle since there are only bond pairs in the structure and no lone pairs. Recall that lone pairs decrease the bond angke from the ideal value in a tetrahedron due to higher repulsion.

8 0

3 years ago

Element whose atoms have completed their outer energy level are the ____​

Element whose atoms have completed their outer energy level are the ____