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3 years ago

When a new substance has formed, has a physical or chemical) change occurred?

Chemistry

1 answer:

avanturin [10]3 years ago

3 0

Answer: A) Chemical Change

Explanation:

A chemical change create a NEW type of matter that CANNOT be reversed!

Example: Spolied milk

Example: Green tomatoe turns red

Hope it’s helpful! :)

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Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g) If you have 4 moles of zinc and 4 moles of hydrochloric acid, which of these would be the l

Y_Kistochka [10]

Answer:

D) hydrochloric acid.

Explanation:

The balanced equation for the mentioned reaction is:

Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g),

It is clear that 1.0 moles of Zn react with 2.0 moles of HCl to produce 1.0 moles of ZnCl₂ and 1.0 mole of H₂.

From stichiometry; Zn reacts with HCl with (1: 2) molar ratio.

∴ 2.0 mol of Zn (the remaining 2.0 mol is in excess) react completely with 4.0 mol of HCl with (1: 2) molar ratio.

So,

the limiting reactant is HCl and the excess reactant is Zn.

Thus, the right choice is: D) hydrochloric acid.

8 0

4 years ago

How many grams of sulfur (S8S8) must be dissolved in 100.0 g naphthalene (C10H8C10H8) to make a 0.11 mm solution

Rainbow [258]

Answer:

5.64x10⁻³ g of S₈S₈

Explanation:

We consider mm as milimolal

Milimolal = molal . 1000

Molal are the moles of solute contained in 1kg of solvent.

Solute → Sulfur (S₈S₈)

Solvent → naphthalene

0.11 mm / 1000 = 1.1x10⁻⁴ molal

moles of solute / kg of solvent = 1.1x10⁻⁴ molal

moles of solute / 0.1 kg of solvent = 1.1x10⁻⁴ molal

moles of solute = 1.1x10⁻⁴ m/kg . 0.1kg → 1.1ₓ10⁻⁵ moles

Molar mass S₈S₈ = 512.96 g/m

1.1ₓ10⁻⁵ mol . 512.96 g/m = 5.64x10⁻³ g

4 0

3 years ago

Consider the following reaction at equilibrium: 2NH3 (g) N2 (g) + 3H2 (g) Le Châtelier's principle predicts that the moles of H2

Lilit [14]

Answer:

A decrease in the total volume of the reaction vessel (T constant)

Explanation:

Le Châtelier's principle predicts that the moles of H2 in the reaction container will increase with a decrease in the total volume of the reaction vessel.
According to the Le Chatelier's principle, when a chnage is a applied to a system at equilibrium, then the equilibrium will shift in a way that counteracts the effect causing it.
In this case, a decrease in volume means there is an increase in pressure, therefore the equilibrium will shift towards the side with the fewer number of moles of gas.

3 0

4 years ago

Be sure to answer all parts.

kondaur [170]

Answer:

154.44 Kg of H₂

Explanation:

We'll begin by converting 139 Kg of water to grams. This can be obtained as follow:

1 kg = 1000 g

Therefore,

139 kg = 139 kg × 1000 g / 1 Kg

139 Kg = 139000 g

Next, the balanced equation. This is illustrated below:

2H₂ + O₂ —> 2H₂O

Next, we shall determine the mass of H₂ that reacted and the mass of H₂O produced from the balanced equation. This can be obtained as follow:

Molar mass of H₂ = 2 × 1 = 2 g/mol

Mass of H₂ from the balanced equation = 2 × 2 = 4 g

Molar mass of H₂O = (2×1) + 16

= 2 + 16

= 18 g/mol

Mass of H₂O from the balanced equation = 2 × 18 = 36 g

SUMMARY

From the balanced equation above,

4 g of H₂ reacted to produce 36 g of H₂O.

Next, we shall determine the mass of H₂ needed to produce 139 kg (i.e 139000 g) of H₂O. This can be obtained as follow:

From the balanced equation above,

4 g of H₂ reacted to produce 36 g of H₂O.

Therefore Xg of H₂ will react to produce 139000 g of H₂O i.e

Xg of H₂ = (4 × 139000)/36

Xg of H₂ = 154444 g

Finally, we shall convert 154444 g to kg this can be obtained as follow:

1000 g = 1 Kg

Therefore,

154444 g = 154444 g × 1 Kg / 1000 g

154444 g = 154.44 Kg

Thus, 154.44 Kg of H₂ is needed to produce 139 Kg of water H₂O

6 0

3 years ago

Claim how the ecosystem is changing.

Maslowich

Answer:

The environment Ecosystems are also affected by climate change. Habitats are being modified, the timing of events such as flowering and egg laying are shifting, and species are altering their home ranges. Changes are also occurring to the ocean.

Explanation:

6 0

3 years ago