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3 years ago

A substance that cannot be separated into simpler substances by physical or chemical means is a

1 answer:

Montano1993 [528]3 years ago

7 0

Pure Substance- Element

Explanation:

Pure Substance VS. Mixture:
A pure Substance CANNOT be separated by physical changes, but a Mixture can.

PURE SUBSTANCE: Element VS. Compound:
An Element is one simple atom while a compound is two or more.
Example: Al (Aluminum) is an Element. CaCl (Calcium Chloride) is a compound.
You can split a compound with chemical changes because if you were to take the example, it would be a Calcium atom and a Chlorine atom.
You CANNOT split a single atom (Element) unless you want to make an atomic bomb which takes a lot of energy and you don’t want to destroy the whole world.

MIXTURE: Homogeneous VS. Heterogeneous:

Homo- mixed; cannot differentiate pieces
Hetero- can differentiate pieces
EX: homo- ketchup (can you see the difference in the vinegar and tomato paste? No)
Hetero- chicken noodle soup (there’s broth, chicken, peas, carrots, and other things)

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Identify the property of the substance that is changing. A. composition B. volume C. boiling point

Colt1911 [192]

Property of Volume changes.

7 0

3 years ago

Read 2 more answers

HURRY HELP 10 POINTS ILL GOVE BRAINLIEST I HAVE TO PASS PICTURE PROVIDED

kramer

Answer:

C₃H₄O₄

Explanation:

In order to get the empirical formula of a compound, we have to follow a series of steps.

Step 1: Divide the percent by mass of each element by its atomic mass.

C: 34.6/12.01 = 2.88

H: 3.9/1.01 = 3.86

O: 61.5/16.00 = 3.84

Step 2: Divide all the numbers by the smallest one, i.e., 2.88

C: 2.88/2.88 = 1

H: 3.86/2.88 ≈ 1.34

O: 3.84/2.88 ≈ 1.33

Step 3: Multiply all the numbers by a number that makes all of them integer

C: 1 × 3 = 3

H: 1.34 × 3 = 4

O: 1.33 × 3 = 4

The empirical formula is C₃H₄O₄.

5 0

3 years ago

Please answer asap need it by Wednesday morning

yarga [219]

The answer to this problem is quite simple, it’s 9

4 0

3 years ago

20cm of 0.09M solution of H2SO4. requires 30cm of NaOH for complete neutralization. Calculate the

kirill115 [55]

Answer:

Choice A: approximately $0.12\; \rm M$ .

Explanation:

Note that the unit of concentration, $\rm M$ , typically refers to moles per liter (that is: $1\; \rm M = 1\; \rm mol\cdot L^{-1}$ .)

On the other hand, the volume of the two solutions in this question are apparently given in $\rm cm^3$ , which is the same as $\rm mL$ (that is: $1\; \rm cm^{3} = 1\; \rm mL$ .) Convert the unit of volume to liters:

$V(\mathrm{H_2SO_4}) = 20\; \rm cm^{3} = 20 \times 10^{-3}\; \rm L = 0.02\; \rm L$ .
$V(\mathrm{NaOH}) = 30\; \rm cm^{3} = 30 \times 10^{-3}\; \rm L = 0.03\; \rm L$ .

Calculate the number of moles of $\rm H_2SO_4$ formula units in that $0.02\; \rm L$ of the $0.09\; \rm M$ solution:

$\begin{aligned}n(\mathrm{H_2SO_4}) &= c(\mathrm{H_2SO_4}) \cdot V(\mathrm{H_2SO_4})\\ &= 0.02 \; \rm L \times 0.09 \; \rm mol\cdot L^{-1} = 0.0018\; \rm mol \end{aligned}$ .

Note that $\rm H_2SO_4$ (sulfuric acid) is a diprotic acid. When one mole of $\rm H_2SO_4$ completely dissolves in water, two moles of $\rm H^{+}$ ions will be released.

On the other hand, $\rm NaOH$ (sodium hydroxide) is a monoprotic base. When one mole of $\rm NaOH$ formula units completely dissolve in water, only one mole of $\rm OH^{-}$ ions will be released.

$\rm H^{+}$ ions and $\rm OH^{-}$ ions neutralize each other at a one-to-one ratio. Therefore, when one mole of the diprotic acid $\rm H_2SO_4$ dissolves in water completely, it will take two moles of $\rm OH^{-}$ to neutralize that two moles of $\rm H^{+}$ produced. On the other hand, two moles formula units of the monoprotic base $\rm NaOH$ will be required to produce that two moles of $\rm OH^{-}$ . Therefore, $\rm NaOH$ and $\rm H_2SO_4$ formula units would neutralize each other at a two-to-one ratio.

$\rm H_2SO_4 + 2\; NaOH \to Na_2SO_4 + 2\; H_2O$ .

$\displaystyle \frac{n(\mathrm{NaOH})}{n(\mathrm{H_2SO_4})} = \frac{2}{1} = 2$ .

Previous calculations show that $0.0018\; \rm mol$ of $\rm H_2SO_4$ was produced. Calculate the number of moles of $\rm NaOH$ formula units required to neutralize that

$\begin{aligned}n(\mathrm{NaOH}) &= \frac{n(\mathrm{NaOH})}{n(\mathrm{H_2SO_4})}\cdot n(\mathrm{H_2SO_4}) \\&= 2 \times 0.0018\; \rm mol = 0.0036\; \rm mol\end{aligned}$ .

Calculate the concentration of a $0.03\; \rm L$ solution that contains exactly $0.0036\; \rm mol$ of $\rm NaOH$ formula units:

$\begin{aligned}c(\mathrm{NaOH}) &= \frac{n(\mathrm{NaOH})}{V(\mathrm{NaOH})} = \frac{0.0036\; \rm mol}{0.03\; \rm L} = 0.12\; \rm mol \cdot L^{-1}\end{aligned}$ .

3 0

3 years ago

Explain why lime is added to lakes. Refer to the problem that exists and what lime does to the lakes.

Darya [45]

Explanation:

Lime is an oxide of calcium(CaO). As a metallic oxide, it produces a basic solution when it reacts with water.

The main reason why lime is added to lakes is to reduce acidity in the lake water.

Bottom muds in lakes are usually acidic and makes the water hypertonic. When lime is added, it reduces the pH of the water and causes acidity to reduce.

Lime also helps to reduce the hardness of lake water to a good level.
Lime also helps to release nutrients useful for photosynthesis of plants in the lake.

Learn more:

Neutralization brainly.com/question/5544078

#learnwithBrainly

8 0

4 years ago