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4 years ago

Which statements correctly describe atmospheric pressure?

Chemistry

1 answer:

djyliett [7]4 years ago

7 0

Answer: Atmospheric pressure is the force per unit area exerted by the weight of the atmosphere.

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What are 5 physical changes in matter

Gennadij [26K]

Answer:

cutting, bending, dissolving, freezing, and boiling

Explanation:

A physical change is a change in one or more physical properties of matter without any change in chemical properties. In other words, matter doesn't change into a different substance in a physical change. Examples of physical change include but are not limited to, from solid to liquid or from liquid to gas are also physical changes.

3 0

3 years ago

An ordered list of chemical substances is shown.

alina1380 [7]

Answer : The correct option is, (C) 2, 4 and 5.

Explanation :

Combustion reaction : It is a type of reaction in which a hydrocarbon react with an oxygen molecule to give carbon dioxide, water as a product.

For example : Methane react with oxygen to give carbon dioxide and water.

$CH_4+2O_2\rightarrow CO_2+2H_2O$

In the given list of chemical substances, $CuO,Cu_2O,Li_2O$ are in oxide form. They can not be both reactant and product of a single combustion reaction.

In the given list, $C_2H_5NH_2$ is the only hydrocarbon which shows a combustion reaction. That means $C_2H_5NH_2$ react with $O_2$ to give $CO_2,H_2O$ and $N_2$ as a product.

The balanced combustion reaction of $C_2H_5NH_2$ is,

$20C_2H_5NH_2+40O_2\rightarrow 40CO_2+7H_2O+10N_2$

Therefore, the correct answer is, (C) 2, 4, and 5.

8 0

3 years ago

100 POINTS!!!! Please I need this page done lol

Alenkinab [10]

Answer:

okay.. Questions?????????

5 0

3 years ago

When 0.200 grams of Al reacts with 15.00 mL of a 0.500 M copper(II) chloride solution, how many moles of solid Cu would be produ

Naddik [55]

When The balanced equation is:
2Al + 3CuCl2 ⇒3 Cu + 2AlCl3
So, we want to find the limiting reactant:
1- no. of moles of 2Al = MV/n = (Wt * V )/ (M.Wt*n*V) = Wt / (M.Wt *n)

where M= molarity, V= volume per liter and n = number of moles in the balanced equation.
by substitute:
∴ no. of moles of 2Al = 0.2 / (26.98 * 2)= 0.003706 moles.
2- no.of moles of 3CuCl2= M*v / n = (0.5*(15/1000)) / 3= 0.0025 moles.
So, CuCl2 is determining the no.of moles of the products.
∴The no. of moles of 3Cu = 0.0025 moles.
∴The no.of moles of Cu= 3*0.0025= 0.0075 moles.
and ∵ amount of weight (g)= no.of moles * M.Wt = 0.0075 * M.wt of Cu
= 0.0075 * 63.546 =0.477 g

3 0

3 years ago

As with other ionic compounds, potassium bromate, KBrO3, dissociates into ions when it dissolves in water. If 13.8 g of KBrO3 is

chubhunter [2.5K]

Answer:

ΔH of dissociation is 38,0 kJ/mol

Explanation:

The dissociation reaction of KBrO₃ is:

KBrO₃ → K⁺ + BrO₃⁻ 

This dissolution consume heat that is evidenced with the decrease in water temperature.

The heat consumed is:

q = CΔTm

Where C is specific heat of water (4,186 J/mol°C)

ΔT is the temperature changing (18,0°C - 13,0°C = 5,0°C)

And m is mass of water (150,0 mL ≈ 150,0 g)

Replacing, heat consumed is:

q = 3139,5 J ≡ 3,14 kJ

13,8 g of KBrO₃ are:

13,8 g×(1mol/167g) = 0,0826 moles

Thus, ΔH of dissociation is:

3,14kJ / 0,0826mol = 38,0 kJ/mol

I hope it helps!

3 0

3 years ago