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3 years ago

What are other signs of chemical change

1 answer:

3 0

Some signs of a chemical change are a change in color and the formation of bubbles. The five conditions of chemical change: color chage, formation of a precipitate, formation of a gas, odor change, temperature change.

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Its difficult to measure the volume of gas. Why??

SVEN [57.7K]

Answer:

Its difficult to measure the volume of gas because its hard to make sure its only a uniform layer of gas in what ever youre measuring in it.

Explanation:

hope it help u

4 0

3 years ago

How many mL of 2.5M HCl would be needed to completely neutralize a standard solution of 0.53M NaOH in a titration

Elena L [17]

Answer:

Amount of HCL = 0.00318 L of 3.18 ml

Explanation:

Given:

HCL = 2.5 M

NaOH = 0.53 M

Amount of NaOH = 15 ml = 0.015 L

Find:

Amount of HCL

Computation:

HCL react with NaOH

HCl + NaOH ⇒ NaCl + H₂O

So,

Number of moles = Molarity × volume

Number of moles of NaOH = 0.53 × 0.015

Number of moles of NaOH = 0.00795 moles

So,

Number of moles of HCl needed = 0.00795 mol es

So,

Volume = No. of moles / Molarity

Amount of HCL = 0.00795 / 2.5

Amount of HCL = 0.00318 L of 3.18 ml

4 0

3 years ago

Consider an insulated container in which water (2.58 g) solidifies at 0 oC and 1 atm on the surface of a 55 g aluminum block. As

yarga [219]

Answer:

17.41°C is the change in temperature of the aluminum block.

Explanation:

Latent heat of fusion water = 334 J/g

Heat required to freeze 1 gram of water = -334 J

Heat required to freeze 2.58 grams of water = Q

$Q=2.58 g\times (-334 J/g)=-861.72 J$

Heat lost by water will be equal to heat gained by the aluminum block

$Q'=-Q$

$Q'= -(-861.72 J)=861.72 J$

Formula used to calculate heat absorbed by substance:

$Q=mc\Delta T$

Where:

Q = heat absorbed by substance

c = specific heat of substance

m = Mass of the substance

ΔT = change in temperature of the substance

We have :

Mass of aluminum block= m= 55 g

Heat capacity of aluminum = c = 0.9 J/g°C

Change in temperature of the aluminum block= ΔT = ?

Heat absorbed by the aluminum = Q'

$861.72 J=55 g\times 0.9 J/g^oC\times \Delta T$

$\Delta T=17.41 ^oC$

17.41°C is the change in temperature of the aluminum block.

8 0

4 years ago

Number 2 how many moles of propane (C3H8) are there in 6.2 g of propane? Correct answer will get brainliest.

skad [1K]

In 1 mole of propane, there are 44 grams
so, X moles = 6.2 grams
Cross multiply: 44x = 6.2
x = 0.14 moles
(In scientific notation) The answer is B

6 0

3 years ago

How is energy level different from orbital?

poizon [28]

Answer:

When an electron is in a particular energy level, it is more likely to be found in some parts of that level than in others. These parts are called orbitals. Orbitals of equivalent energy are grouped in sublevels. Each orbital can contain a maximum of two electrons.

5 0

3 years ago