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3 years ago

What human development period 2 years and 12 years called

Chemistry

2 answers:

nikdorinn [45]3 years ago

7 0

Answer:

In these lessons, students become familiar with the four key periods of growth and human development: infancy (birth to 2 years old), early childhood (3 to 8 years old), middle childhood (9 to 11 years old), and adolescence (12 to 18 years old).

daser333 [38]3 years ago

7 0

Children between the ages of 6 and 12 are in the age period commonly referred to as middle childhood.

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Show that, with appropriate coefficients, the two reactions can be summed to give the overall oxidation of SO2 by O2 to give SO3

SIZIF [17.4K]

Answer:

See explanation

Explanation:

We know that the process of the oxidation of SO2 to SO3 is catalysed by NO2 gas. It occurs in two stages and i will show the balanced reaction equation of the both stages below;

Step 1

2NO2(g) + 2SO2(g) ------> 2NO(g) + 2SO3(g)

Step 2

2NO(g) + O2(g) -------> 2NO2(g)

So, the overall reaction equation is;

2SO2(g) + O2(g) ------> 2SO3(g)

5 0

3 years ago

Which observation provided Albert Einstein the clue that he needed to explain the photoelectric effect? Light is made up of extr

Aliun [14]

The correct answer is

Energy of electrons depends on light’s frequency, not intensity.

As per photoelectric effect, if we incident a light on metal surface it will results into emission of electron from it

if we increase the number of photons the number of electrons will increase however if we increase the frequency the number of photons will not increase

While if we increase frequency the energy of electrons will increase as

Energy of photon = Work function of metal + kinetic energy of electrons

7 0

2 years ago

Read 2 more answers

200.0 mL of 3.85 M HCl is added to 100.0 mL of 4.6 M barium hydroxide. The reaction goes to completion. What is the concentratio

Ede4ka [16]

Answer:

2.387 mol/L

Explanation:

The reaction that takes place is:

2HCl + Ba(OH)₂ → BaCl₂ + 2H₂O

First we calculate how many moles of each reagent were added:

HCl ⇒ 200.0 mL * 3.85 M = 203.85 mmol HCl

Ba(OH)₂ ⇒ 100.0 mL * 4.6 M = 460 mmol Ba(OH)₂

460 mmol of Ba(OH)₂ would react completely with (2*460) 920 mmol of HCl. There are not as many mmoles of HCl so Ba(OH)₂ will remain in excess.

Now we calculate how many moles of Ba(OH)₂ reacted, by converting the total number of HCl moles to Ba(OH)₂ moles:

203.85 mmol HCl * $\frac{1mmolBa(OH)_{2}}{2mmolHCl}$ = 101.925 mmol Ba(OH)₂

This means the remaining Ba(OH)₂ is:

460 mmol - 101.925 mmol = 358.075 mmoles Ba(OH)₂

There are two OH⁻ moles per Ba(OH)₂ mol:

OH⁻ moles = 2 * 358.075 = 716.15 mmol OH⁻

Finally we divide the number of OH⁻ moles by the total volume (100 mL + 200 mL):

716.15 mmol OH⁻ / 300.0 mL = 2.387 M

So the answer is 2.387 mol/L

7 0

3 years ago

The two balanced equations (1) and (2) are for reactions in which gaseous carbon dioxide is produced from the combustion of (1)

V125BC [204]

Answer:

2.0 mol of oxygen are consumed.

Step-by-step explanation:

You know that you will need a balanced equation with masses, moles, and molar masses, so gather all the information in one place.

M_r: 28.0 44.0

CO + ½O₂ ⟶ CO₂ + 67.6 kcal

m/g: 112

Step 1. Convert grams of CO to moles of CO

1 mol CO = 28.0 g CO

Moles of CO = 112 × 1/28.0

Step 2. Convert moles of CO to moles of CO₂.

The molar ratio is 1 mol CO₂ to 1 mol CO

Moles of CO₂ = 4.000 × 1/1

Moles of CO₂ = 4.00 mol CO₂

Option A is wrong.

Step 3. Calculate the amount of heat generated.

q = ΔH

The conversion factor is 67.6 kcal/1 mol CO₂

q = 4.00 × 67.6

q = 270 kJ

Option B is wrong, because it gives the heat generated by 1 mol of CO.

Step 4. Calculate the moles of O₂ consumed

Moles of O₂ = 2.00 mol O₂

Option C is correct.

Step 5. Calculate the moles of CO₂ formed

Already done in Step 2.

Moles of CO₂ = 4.00 mol CO₂

Option D is wrong.

Step 6. Calculate the moles of O₂ produced

Already done in Step 4.

Moles of O₂ = 2.00 mol O₂

Option E is wrong. 

3 0

3 years ago

A chemistry student was asked to calculate the number of moles of iron required to react with 1.20 mol of oxygen to produce iron

Delicious77 [7]

Answer:Write and balance the equation

4Fe + 3O2 -> 2Fe2O3

0.32 mol Fe x 2 mol Fe2O3 / 4 mol Fe =

0.16 mol of Fe2O3

Explanation:

8 0

3 years ago