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2 years ago

What makes physical change a physical change and a chemical change a chemical change

2 answers:

6 0

A physical change is any change in a substances form that does not change its chemical makeup. Examples of physical changes are breaking a stick or melting ice. A chemical change occurs when atoms of a substance are rearranged, and the bonds between the atoms are broken or formed. HOPE THIS HELPS!!

katrin [286]2 years ago

6 0

Answer:

A physical change is reversible and the changes made are only physical (smell, physical state, volume, etc) and most importantly no new substance is formed. In a chemical change, a new substance is formed, the chemical properties are changed, and it's permanent.

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C12H7Cl3FNaO2 what are them elements in that chemical formula

LuckyWell [14K]

Assuming you are asking for the names of the elements in that formula , the answer is

carbon
hydrogen
chlorine
fluorine
sodium
oxygen

8 0

3 years ago

If 4520 kj of heat is needed to boil a sample of water, what is the mass of water

Cerrena [4.2K]

Answer:

1,085g of water

Explanation:

If we have the value 4520kj is because the question is related to Energy and heat capacity. In this case, the law and equation that we use is the following:

Q= m*C*Δt where;

Q in the heat, in this case: 4520kj

m is the mas

Δt= is the difference between final-initial temperature (change of temperature), in this exercise we don´t have temperatura change.

In order to determine the mass, I will have the same equation but finding m

m= Q/C*Δt without m=Q/C

So: m= 4,520J/4.18J/g°C

m= 1,0813 g

5 0

3 years ago

Find the equation of directrix of the parabola is given by 64x equals to -ySquare

ANEK [815]

Answer:

Given equation of parabola is

and

=64x ......(i)

The point at which the tangent to the curve is parallel to the line is the nearest point on the curve.

On differentiating both sides of equation (i), we get

2 y

d y

=64

⇒

d y

and

Also, slope of the given line is −

∴−

and

⇒and=−24

From equation (i), (−24)

=64x⇒x=9

∴ the required point is (9,−24)

Explanation:

This is the correct answer you want

please follow the

5 0

3 years ago

What quantity is measured in mol/dm³?

natima [27]

L
$M = \frac{n}{V} \\ M = \frac{mol}{L} \\ or \\ M = \frac{mol}{ {dm}^{3} }$
mol/dm³ is measure for molarity

3 0

3 years ago

How many grams are in 3.14 moles of PI₃?

OverLord2011 [107]

Answer:

$\boxed {\boxed {\sf 1290 \ g \ PI_3}}$

Explanation:

We want to convert from moles to grams, so we must use the molar mass.

<h3>1. Molar Mass</h3>

The molar mass is the mass of 1 mole of a substance. It is the same as the atomic masses on the Periodic Table, but the units are grams per mole (g/mol) instead of atomic mass units (amu).

We are given the compound PI₃ or phosphorus triiodide. Look up the molar masses of the individual elements.

Phosphorus (P): 30.973762 g/mol
Iodine (I): 126.9045 g/mol

Note that there is a subscript of 3 after the I in the formula. This means there are 3 moles of iodine in 1 mole of the compound PI₃. We should multiply iodine's molar mass by 3, then add phosphorus's molar mass.