All categories

3 years ago

Why aren't descriptive investigations repeatable?

2 answers:

8 0

In descriptive investigations, we still haven't formed any hypothesis yet so we seek information by asking question.

It's not repeatable because repeating the questions over and over again without any clue about what we want to seek is completely waste of time.

Hope this helps xox :)

Goryan [66]3 years ago

3 0

Answer:

Descriptive investigations are not repeatable because they are based only on observations made at a single point in time. The results may vary at a different time. In addition, descriptive investigations do not contain variables that may indicate cause-and-effect relationships.

Explanation:

I just did it and that was the given answer

You might be interested in

A 3.452 g sample containing an unknown amount of a Ce(IV) salt is dissolved in 250.0 mL of 1 M H2SO4. A 25.00 mL aliquot is anal

Olenka [21]

Answer:

The weight percent in the sample is 17,16%

Explanation:

The dissolution of the Ce(IV) salt provides free Ce⁴⁺ that reacts, thus:

2Ce⁴⁺ + 3I⁻ → 2Ce³⁺ + I₃⁻

I₃⁻ + 2S₂O₃²⁻ → 3I⁻ + S₄O₆²⁻

The moles in the end point of S₂O₃⁻ are:

0,01302L×0,03247M Na₂S₂O₃ = 4,228x10⁻⁴ moles of S₂O₃²⁻.

As 2 moles of S₂O₃⁻ react with 1 mole of I₃⁻, the moles of I₃⁻ are:

4,228x10⁻⁴ moles of S₂O₃⁻× $\frac{1molI_{3}^-}{2molS_{2}O_{3}^{2-}}$ = 2,114x10⁻⁴ moles of I₃⁻

As 2 moles of Ce⁴⁺ produce 1 mole of I₃⁻, the moles of Ce⁴⁺ are:

2,114x10⁻⁴ moles of I₃⁻× $\frac{2molCe^{4+}}{1molI_{3}^-}$ = 4,228x10⁻⁴ moles of Ce(IV).

These moles are:

4,228x10⁻⁴ moles of Ce(IV)× $\frac{140,116g}{1mol}$ = 0,05924 g of Ce(IV)

As was taken an aliquot of 25,00mL from the solution of 250,0mL:

0,05924 g of Ce(IV)× $\frac{250,0mL}{25,00mL}$ =0,5924g of Ce(IV) in the sample

As the sample has 3,452g, the weight percent is:

0,5924g of Ce(IV) / 3,452g × 100 = 17,16 wt%

I hope it helps!

3 0

3 years ago

1. How to elements differ from compounds?

REY [17]

Answer:

A compound contains atoms of different elements chemically combined together in a fixed ratio. An element is a pure chemical substance made of same type of atom. ... Elements contain only one type of atom.

Explanation:

5 0

3 years ago

what type of element can turn into both solid and liquid form depending on the temperature of its surroundings ?

lorasvet [3.4K]

Answer:

An Atom can turn into both solid and liquid form depending on the temperature of its surroundings

Explanation:

Scientists have discovered a new state of physical matter in which atoms can exist as both solid and liquid simultaneously. Researchers have found, however, that some elements can, when subjected to extreme conditions, take on the properties of both solid and liquid states.

7 0

2 years ago

Read 2 more answers

How many moles of ammonium sulfate can be from the reaction of 30.0 mol of NH3 with H2SO4 according to the following equation: 2

marysya [2.9K]

Answer:

15 moles of ammonium sulfate would be formed from 30 moles of ammonia.

Explanation:

Given data:

Number of moles of ammonium sulfate formed = ?

Number of moles of ammonia = 30.0 mol

Solution:

Chemical equation:

2NH₃ + H₂SO₄ → (NH₄)₂SO₄

Now we will compare the moles of ammonium sulfate with ammonia.

NH₃ : (NH₄)₂SO₄

2 : 1

30.0 : 1/2×30.0 = 15.0 mol

So 15 moles of ammonium sulfate would be formed from 30 moles of ammonia.

7 0

2 years ago

How many bonds would be needed when bonding 2 atoms of nitrogen to achieve a full octet for both atoms?

andriy [413]

Answer:

3 bonds are needed.

Explanation:

The electrons that are involved in chemical bonding are those in the outer shell of the highest energy level of the atom. The electron configuration of nitrogen (N) is 1s²2s²2p³. That means thy at each nitrogen atom has 5 valence electrons: 2 electrons in the 2s orbital and 3 electrons in the 2p orbital. To fullfil the octet, each nitrogen atom needs 3 electrons. So, they can share each other 3 electrons to form 3 simple bonds. Therefore, the nitrogen molecule (N₂) has 3 bonds involving 6 bonding electrons or a triple bond.

8 0

2 years ago