All categories

4 years ago

Musiclover10045 HELPPPPPPPPPPPPPPP

Chemistry

2 answers:

leonid [27]4 years ago

5 0

Answer:

1 ) A change in color of substance

2) The given statement is false.

3) A burning of candle is a chemical change.

Explanation:

A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.

Example : Melting of ice

Physical property is defined as the property which can be measured and whose value describes the state of physical system. For Example: State, density etc.

A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.

Example: Corrosion of iron called as rusting.

Chemical property is defined as the property of a substance which is observed during a reaction where the chemical composition identity of the substance gets changed.

Precipitate is solid substance formed from the mixing of two different solutions.

Zinaida [17]4 years ago

4 0

1. a change in the color of a substance

2. False, a precipitate is a solid not a gas

3. a burning candle

You might be interested in

What is the chemical formula for sodium sulfate?

yan [13]

Hello!

When finding the chemical formula of a compound, we will need to find the charges of each element/bond.

Looking at our period table, sodium has a +1 charge, written as Na 1+, and sulfate has a charge of -2, and it is written as SO4 2-.

Now, we need to make the charges equivalent. To do this, we need to "criss-cross" the charges. This means that sodium will need to additional atoms to make the charges equal, and sulfate will need one.

Therefore, the chemical formula for sodium sulfate is: Na2SO4.

5 0

3 years ago

How many atoms are there in 5.00 mol of sulphur (S)?

Mumz [18]

Answer:

3.01 × 10²⁴ atoms S

General Formulas and Concepts:

Chemistry - Atomic Structure

Using Dimensional Analysis
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Explanation:

Step 1: Define

5.00 mol S

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

$5.00 \ mol \ S(\frac{6.022 \cdot 10^{23} \ atoms \ S}{1 \ mol \ S} )$ = 3.011 × 10²⁴ atoms S

Step 4: Check

We are given 3 sig figs. Follow sig fig rules and round.

3.011 × 10²⁴ atoms S ≈ 3.01 × 10²⁴ atoms S

6 0

3 years ago

Salt in crude oil must be removed before the oil undergoes processing in a refinery. The

irina1246 [14]

Answer:

$\large \boxed{0.64 \, \%}$

Explanation:

Assume you are using 1 L of water.

Then you are washing 4 L of salty oil.

1. Calculate the mass of the salty oil

Assume the oil has a density of 0.86 g/mL.

$\text{Mass of oil} = \text{4000 mL} \times \dfrac{\text{0.86 g}}{\text{1 mL}} = \text{3440 g}$

2. Calculate the mass of salt in the salty oil

$\text{Mass of salt} = \text{3440 g} \times \dfrac{\text{5 g salt}}{\text{100 g oil}} = \text{172 g salt}$

3. Calculate the mass of salt in the spent water

$\text{Mass of salt} = \text{1000 g water} \times \dfrac{\text{15 g salt}}{\text{100 g water}} = \text{150 g salt}$

4. Mass of salt remaining in washed oil

Mass = 172 g - 150 g = 22 g

5. Concentration of salt in washed oil

$\text{Concentration} = \dfrac{\text{22 g}}{\text{3440 g}} \times 100 \, \% = \mathbf{0.64 \, \%}\\\\\text{The concentration of salt in the washed oil is $\large \boxed{\mathbf{0.64 \, \%}}$}$

3 0

3 years ago

Changing the number of ___ gives an atom a neutral charge or causes it to take on a positive or negative charge. (pick on that b

artcher [175]

Answer:

Explanation:

7 0

3 years ago

What is always true of a strong acid?

sveta [45]

Strong acids provide more H+ in the aqueous solution than the weak acids. This excess amount of H+ conducts more electricity in the solution.

Explanation:

The strong acid provides more H+ ion whereas the weak acids produce less H+ in the aqueous solution resulting in less amount of electricity conduction in the solution.

Weak acid- lesser amount of H+ produced

Strong acid- greater amount of H+ ( proton) produced.

4 0

3 years ago

Read 2 more answers