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4 years ago

Which of the following is a chemical change?

1 answer:

6 0

Hey there! :D

Which of the following is a chemical change?

A chemical change is a change that alters the makeup of a substance or something. It changes what it is made of. You cannot alter chemical changes.

Boiling water can go back to regular room temperature water. This is not a chemical change.

Melting a cube of ice is not a chemical change. We can freeze the water again to make it ice.

Dissolving 10 grams of salt in water is not a chemical change. You can boil the water and split the salt and water. People do this with Ocean water, to make it drinkable.

Splitting water into hydrogen and oxygen is a chemical change. You change the makeup of the water. It is now separate hydrogen and oxygen. It is not water anymore. "D" is the answer.

I hope this helps!
~kaikers

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Type the correct answer in each box.

krok68 [10]

Answer:

2KI → 2K + I₂

Explanation:

(not my definition, but form a trustworthy source)

The definition of a decomposition reaction is:

a chemical reaction in which one reactant breaks down into two or more products.

In this case, potassium iodide will decompose into potassium and iodine.

2KI → 2K + 2I

2 Potassium and 2 Iodine on both sides, so equation is balanced.

Or, it can be written as 2KI → 2K + I₂

8 0

2 years ago

Does the lewis structure depict a neutral molecule or an ion? does the lewis structure depict a neutral molecule or an ion? the

Lina20 [59]

is this supposed to sound like an actual question? it looks like something computer generated to me, but, yes?

6 0

4 years ago

Read 2 more answers

Is this right.??? I’m stuck on this .

Katyanochek1 [597]

Answer:

yes

Explanation:

8 0

4 years ago

A solution of 0.170 mol/l ion strength is prepared using NaNO3 (solid) and Na2SO4 (solid). Calculate the mass of each salt that

just olya [345]

Answer:

1,06 g of NaNO₃ and 1,42 g of Na₂SO₄

Explanation:

In water, NaNO₃ and Na₂SO₄ dissociates as:

NaNO₃ → Na⁺ + NO₃⁻

Na₂SO₄ → 2 Na⁺ SO₄²⁻

The ionic strength is difined as:

∑ $\frac{C_{i} Z_{i}^2}{2}$ Where Ci and Zi are concentration and charge of each ion in solution. Thus:

$\frac{C_{Na+}+C_{NO3-}+4C_{SO4-}}{2}$ = 0,170 mol/L

Knowing $C_{Na^+}$ = 0,130 mol/L you can obtain:

0,210 mol/L = $C_{NO_{3}^-}+4C_{SO_{4}^{2-}}$ (1)

The 0,130 mol/L of Na⁺ comes from $C_{NaNO_{3}}+2C_{Na_{2}SO_{4}}$ , thus:

0,130 mol/L = $C_{NO_{3}^-}+2C_{SO_{4}^{2-}}$ (2)

Replacing (2) in (1)

$C_{NO_{3}^-} = 0,050 M$

And:

$C_{SO_{4}^{2-}} = 0,040 M$

The 0,050 M of NO₃⁻ comes from:

0,050M×0,250L× $\frac{84,99 g}{1molNaNO_{3}}$ = 1,06 g of NaNO₃

The 0,040 M of SO₄⁻ comes from:

0,040M×0,250L× $\frac{142,04 g}{1molNa_{2}SO_{4}}$ = 1,42 g of Na₂SO₄

I hope it helps!

5 0

3 years ago

Please choose the correct number (associated with the vocab word) from the drop down menu that matches the definition

baherus [9]

Q1. -------- a specific way that a quantity may increase over time

1. Exponential growth

2. Biotic

3. Trait

4. Succession

Answer:

1. Exponential growth

Explanation:

Exponential growth is a specific way that a quantity may increase over time. The instantaneous rate of change of a quantity with respect to time is proportional to the quantity itself. When growth becomes more rapid in relation to the growing total number, then it becomes exponential.

Example: Latest updates of COVID-19. For today, the number of infected people cases from COVID-19 is 190,000. By observing the graph, to reach 100,000 the number of infected patient cases, it took 3 months and the other 90,000 patients were infected in just 15 days.

Q2. ------- is the inherent inclination of a living organism towards a particular complex behavior.

1. Abiotic

2. Biotic

3. Innate behavior

Answer:

3. Innate behavior

Explanation:

Innate behavior is behavior that occurs naturally in all members of a species. These behaviors do not have to be learned or practiced.

Example: When a human baby born, he already knows how to suck mother breast to get milk. He never learned before. As he grew up, he knows how to grasp things.

8 0

4 years ago