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2 years ago

Which of these is an example of a physical change?

Chemistry

1 answer:

Sonja [21]2 years ago

7 0

Answer: a) sugar dissolving in warm water

Explanation: I think this is the best answer because physical changes are usually reversible and no chemical action occurs

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Convert 876 millimeters to grams

PolarNik [594]

Did you mean milliliters? if so your answer would still be 876 because they are equal. I don't think it is possible to convert millimeters and grams :)

6 0

2 years ago

Read 2 more answers

Suppose you have an Internet friend who study chemistry just like you are your friend claims the change from liquid water to wat

svlad2 [7]

It is not a chemical change because a chemical change is when the substance changes to a whole new substance (ex rust on a car) ex2(fire burning wood) it’s not the same substance) it is a physical change because it’s still water basically (ex: like melting ice, it’s still ice( not a whole different substance)

7 0

2 years ago

How many molecules are in 68.0 g of H2S

Kryger [21]

The correct answer is 12.044 × 10²³ molecules.

The molecular mass of H₂S is 34 gram per mole.

Number of moles is determined by using the formula,

Number of moles = mass/molecular mass

Given mass is 68 grams, so no of moles will be,

68/34 = 2 moles

1 mole comprises 6.022 × 10²³ molecules, therefore, 2 moles will comprise = 6.022 × 10²³ × 2

= 12.044 × 10²³ molecules.

3 0

2 years ago

What mass (g) of magnesium nitride (Mg3N2) can be made from the reaction of 1.22 g of magnesium with excess nitrogen? __Mg + __N

Citrus2011 [14]

<h3>Answer:</h3>

1.69 g Mg₃N₂

<h3>General Formulas and Concepts:</h3>

Math

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Chemistry

Atomic Structure

Reading a Periodic Table

Stoichiometry

Using Dimensional Analysis
Reactions RxN

<h3>Explanation:</h3>

Step 1: Define

[RxN - Unbalanced] Mg + N₂ → Mg₃N₂

[RxN - Balanced] 3Mg + N₂ → Mg₃N₂

[Given] 1.22 g Mg

[Solve] grams Mg₃N₂

Step 2: Identify Conversions

[RxN] 3 mol Mg → Mg₃N₂

[PT] Molar Mass of Mg - 24.31 g/mol

[PT] Molar Mass of N - 14.01 g/mol

Molar Mass of Mg₃N₂ - 3(24.31) + 2(14.01) = 100.95 g/mol

Step 3: Stoich

[DA] Set up: $\displaystyle 1.22 \ g \ Mg(\frac{1 \ mol \ Mg}{24.31 \ g \ Mg})(\frac{1 \ mol \ Mg_3N_2}{3 \ mol \ Mg})(\frac{100.95 \ g \ Mg_3N_2}{1 \ mol\ Mg_3N_2})$
[DA] Multiply/Divide [Cancel out units]: $\displaystyle 1.68873 \ g \ Mg_3N_2$

Step 4: Check

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

1.68873 g Mg₃N₂ ≈ 1.69 g Mg₃N₂

8 0

2 years ago

It's actually Science but I didn't find it.

fomenos

Answer:

Forces acting on an object may be balanced or unbalanced. When the forces acting on an object have equal strength and act in opposite directions, they are balanced. These forces cancel out one another, and the motion of the object does not change. When the forces acting on an object are unbalanced, they do not cancel out one another. An unbalanced force acting on an object results in the object’s motion changing. The object may change its speed (speed up or slow down), or it may change its direction. Friction is a force that resists the motion or the tendency toward motion between two objects in contact with each other. Gravity is a force that pulls objects toward one another. For example, Earth pulls all objects toward it.

Explanation:

3 0

2 years ago