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3 years ago

15

A substance formed when two or more chemical elements are chemically bonded together?

1 answer:

Ronch [10]3 years ago

6 0

Answer: a piece of pure matter which we can see from our naked eye is termed as a substance

Explanation:

every substance has physical and chemical properties like;

diamond ,water ,pure sugar ,table salt e.t.c

an element is a substance made up of same type of atoms having same atomic number[protons],and cannot be easily decomposed in to a single substance by ordinary chemical reaction example,.....

gold,copper,zinc and some are in liquid form like mercury,bromine and some are in gases for example, hydrogen ,oxygen, nitrogen

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What gas is used in freezers and fridges?

natta225 [31]

Answer:

Chloro-Flouro-Carbon

Explanation:

Chloro-Flouro-Carbon (CFC Gas) is used as a refrigerant in fridges and freezers.

7 0

2 years ago

A strontium hydroxide solution is prepared by dissolving 10.60 gg of Sr(OH)2Sr(OH)2 in water to make 47.00 mLmL of solution.What

NeTakaya

Answer:

Approximately $1.854\; \rm mol\cdot L^{-1}$ .

Explanation:

Note that both figures in the question come with four significant figures. Therefore, the answer should also be rounded to four significant figures. Intermediate results should have more significant figures than that.

<h3>Formula mass of strontium hydroxide</h3>

Look up the relative atomic mass of $\rm Sr$ , $\rm O$ , and $\rm H$ on a modern periodic table. Keep at least four significant figures in each of these atomic mass data.

$\rm Sr$ : $87.62$ .
$\rm O$ : $15.999$ .
$\rm H$ : $1.008$ .

Calculate the formula mass of $\rm Sr(OH)_2$ :

$M\left(\rm Sr(OH)_2\right) = 87.62 + 2\times (15.999 + 1.008) = 121.634\; \rm g \cdot mol^{-1}$ .

<h3>Number of moles of strontium hydroxide in the solution</h3>

$M\left(\rm Sr(OH)_2\right) =121.634\; \rm g \cdot mol^{-1}$ means that each mole of $\rm Sr(OH)_2$ formula units have a mass of $121.634\; \rm g$ .

The question states that there are $10.60\; \rm g$ of $\rm Sr(OH)_2$ in this solution.

How many moles of $\rm Sr(OH)_2$ formula units would that be?

$\begin{aligned}n\left(\rm Sr(OH)_2\right) &= \frac{m\left(\rm Sr(OH)_2\right)}{M\left(\rm Sr(OH)_2\right)}\\ &= \frac{10.60\; \rm g}{121.634\; \rm g \cdot mol^{-1}} \approx 8.71467\times 10^{-2}\; \rm mol\end{aligned}$ .

<h3>Molarity of this strontium hydroxide solution</h3>

There are $8.71467\times 10^{-2}\; \rm mol$ of $\rm Sr(OH)_2$ formula units in this $47\; \rm mL$ solution. Convert the unit of volume to liter:

$V = 47\; \rm mL = 0.047\; \rm L$ .

The molarity of a solution measures its molar concentration. For this solution:

$\begin{aligned}c\left(\rm Sr(OH)_2\right) &= \frac{n\left(\rm Sr(OH)_2\right)}{V}\\ &= \frac{8.71467\times 10^{-2}\; \rm mol}{0.047\; \rm L} \approx 1.854\; \rm mol \cdot L^{-1}\end{aligned}$ .

(Rounded to four significant figures.)

5 0

3 years ago

What is the diffrence between acidic and basic solutions in working with redox reactions?

Leno4ka [110]

In acidic solutions you have H+ but in basic solutions you have OH-.
You need know that for to balance the reaction.

3 0

3 years ago

Which part of the periodic would contain an element with a partially filled f sublevel

noname [10]

Answer: Lanthanide and actinide series

Explanation: The elements with partially or fully filled f orbitals belong to f block elements.

f block elements include lanthanides and actinides. They are called so the lanthanides contain the first element named as lanthanum and actinides contain first element named as actinium. They are also called as inner transition elements.

All of them have general electronic configuration:

$(n-2)f^{1-14}(n-1)d^{0-10}ns^2$ , where n = 6-7

8 0

3 years ago

Read 2 more answers

How much heat was transferred from 50.0 g of water if the temperature of the water went from 30.0 ° C to 55.0 °? The specific he

Lena [83]

Answer:

Heat transfer = Q = 62341.6 J

Explanation:

Given data:

Heat transfer = ?

Mass of water = 50.0 g

Initial temperature = 30.0°C

Final temperature = 55.0°C

Specific heat capacity of water = 4.184 J/g.K

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 55.0°C - 30.0°C

ΔT = 25°C (25+273= 298 K)

Q = 50.0 g × 4.184 J/g.K ×298 K

Q = 62341.6 J

4 0

3 years ago