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3 years ago

Which property of matter changes during a chemical change but not during a physical change

1 answer:

8 0

Answer:In a physical change, atoms are not rearranged and the matter's physical and chemical properties are unchanged. Chemical changes, on the other hand, rearrange the atoms of matter in new combinations, resulting in matter with new physical and chemical properties.

Explanation:

easy

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I SWEAR THIS IS WAY TOO EASY, WHY AM I THAT STUPID, HELP ME AND ILL MARK U BRAINLIEST

exis [7]

Answer:

i think the first one is gravity and second one is rotation

Explanation:

5 0

2 years ago

How many milliliters of water at 25.0°C with a density of 0.997 g/mL must be mixed with 163 mL of coffee at 97.9°C so that the r

Stolb23 [73]

Answer:

248 mL

Explanation:

According to the law of conservation of energy, the sum of the heat absorbed by water (Qw) and the heat released by the coffee (Qc) is zero.

Qw + Qc = 0

Qw = -Qc [1]

We can calculate each heat using the following expression.

Q = c × m × ΔT

where,

c: specific heat

m: mass

ΔT: change in the temperature

163 mL of coffee with a density of 0.997 g/mL have a mass of:

163 mL × 0.997 g/mL = 163 g

From [1]

Qw = -Qc

cw × mw × ΔTw = -cc × mc × ΔTc

mw × ΔTw = -mc × ΔTc

mw × (54.0°C-25.0°C) = -163 g × (54.0°C-97.9°C)

mw × 29.0°C = 163 g × 43.9°C

mw = 247 g

The volume corresponding to 247 g of water is:

247 g × (1 mL/0.997 g) = 248 mL

8 0

3 years ago

Eading and

4vir4ik [10]

Answer: 25.8 g of $Cl_2$ will be produced from the decomposition of 73.4 g of $AuCl_3$

Explanation:

To calculate the moles :

$\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}$

$\text{Moles of} AuCl_3=\frac{73.4g}{303g/mol}=0.242moles$

The balanced chemical reaction is:

$2AuCl_3\rightarrow 2Au+3Cl_2$

According to stoichiometry :

2 moles of $AuCl_3$ produce = 3 moles of $Cl_2$

Thus 0.242 moles of will produce= $\frac{3}{2}\times 0.242=0.363mol$ of $Cl_2$

Mass of $Cl_2$ = $moles\times {\text {Molar mass}}=0.363mol\times 71g/mol=25.8g$

Thus 25.8 g of $Cl_2$ will be produced from the decomposition of 73.4 g of $AuCl_3$

5 0

2 years ago

Calculate the number of O atoms in 0.364 g of CaSO4 · 2H2O

Nikolay [14]

Answer:

= 7.66 x 10²¹ oxygen atoms in 0.364 grams of CaSO₄·2H₂O

Explanation:

For problems like this posting, one needs an understanding of the following topics:

The definition of the mole

1 mole of substance = mass in grams of substance containing 1 Avogadro's Number ( = 6.023 x 10²³ ) of particles of the specified substance. This is generally one formula weight of the substance of interest. From this, the following equivalent relationships should be memorized:

1 mole = 1 formula weight = 1 mole weight (g)= 6.023 x 10²³ particles

Converting grams to moles:

Given grams => moles = grams/gram formula wt

Converting moles to grams:

Given moles => grams = moles x gram formula wt

_________________________________________________________

Calculate the number of O atoms in 0.364 g of CaSO₄ · 2H₂O.

Given mass CaSO₄ · 2H₂O = 0.364 grams

Formula Wt CaSO₄ · 2H₂O = 172 g/mole

moles CaSO₄ · 2H₂O = mass CaSO4 · 2H2O / formula Wt. CaSO₄ · 2H₂O

= 0.364 g CaSO₄·2H₂O / 172 g CaSO4·2H2O

= (0.364/172) mole CaSO₄·2H₂O

= 2.12 x 10⁻³ mole CaSO₄·2H₂O

∴ number of Oxy (O) atoms in 0.364 grams CaSO₄·2H₂O

= (2.12 x 10⁻³ mole CaSO₄ · 2H₂O)(6.023 x 10²³ molecules CaSO₄· 2H₂O/ mole)

= 1.276876 x 10²¹molecules CaSO₄· 2H₂O CaSO₄2H₂O

= 1.276876 x 10²¹ molecules CaSO₄· 2H₂O x 6 oxygen atoms / molecule

= 7.661256 x 10²¹ oxygen atoms in 0.364 grams of CaSO₄·2H₂O

= 7.66 x 10²¹ oxygen atoms in 0.364 grams of CaSO₄·2H₂O

8 0

2 years ago

Which isomer of 1-tert-butyl-3-ethyl-5-methylcyclohexane below is thermodynamically the most stable?

Agata [3.3K]

<h2>Answer:</h2>

Option A is correct.

<h3>Explanation:</h3>

In the options given below the isomer given in the option A of 1-tert-butyl-5-methylcyclohexane is the most stable of all. The IUPAC name for this compound is 1-tert-butyl-3-ethyl-5-methylbenzene.

7 0

3 years ago