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3 years ago

Help " anyone" plz ....

Chemistry

1 answer:

boyakko [2]3 years ago

5 0

Answer:

letter A. i hope this is correct answer

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Mendeleev organized the elements:

pashok25 [27]

Answer: (3)

Medeleev arranged elements in order of increasing atomic weight and similar properties

He noticed that similar elements were grouped together by using this.

4 0

4 years ago

What is a maximum negative displacement of a wave

AnnZ [28]

The maximum negative displacement of a wave is the same as its amplitude.

As a wave travels through space, its particles are sometimes above the

x-axis (+) and sometimes below it (-).

The maximum displacement from the axis is the amplitude of the wave.

The amplitude of the wave is the same in both the positive and negative directions.

5 0

3 years ago

he combustion of propane (C3H8) is given by the balanced chemical equation C_3H_8+5O_2\longrightarrow3CO_2+4H_2O C 3 H 8 + 5 O 2

Basile [38]

Answer:

290 grams

Explanation:

Let's begin by writing the balanced chemical equations:

$C_{3}H_{8} +5O_{2} --->3CO_{2} +4H_{2}O$

Then we calculate the number of moles in 97g of propane.

n(propane)= $\frac{mass}{molarmass} =\frac{97g}{44.1g/mol}=2.1995mol$

According to the balanced chemical equation, one mole of propane produces 3 moles of carbon dioxide. So the available number of moles of propane must be multiplied by three to work out the number of carbon dioxide produced.

n(carbon dioxide)= 2.1995mol*3 = 6.5985mol

mass(carbon dioxide) = moles * molar mass

= 6.5985 mol * 44.01 g/mol

= 290 grams

4 0

3 years ago

What is the concentration of an unknown Mg(OH)2 solution if it took an average of 15.4mL of

vova2212 [387]

Answer:

0.077M

Explanation:

Step 1:

The balanced equation for the reaction. This is given below:

2HCl + Mg(OH)2 —> MgCl2 + 2H2O

From the balanced equation above,

The mole ratio of the acid (nA) = 2

The mole ratio of the base (nB) = 1

Step 2:

Data obtained from the question.

Concentration of base Cb =...?

Volume of base (Vb) = 10mL

Concentration of acid (Ca) = 0.1M

Volume of acid (Va) = 15.4mL

Step 3:

Determination of the concentration of the base, Mg(OH)2.

The concentration of the base can be obtained as follow:

CaVa/CbVb = nA/nB

0.1 x 15.4 /Cb x 10 = 2/1

Cross multiply to express in linear form

Cb x 10 x 2 = 0.1 x 15.4

Divide both side by 10 x 2

Cb = (0.1 x 15.4) /(10 x 2)

Cb = 0.077M

Therefore, the concentration of the base, Mg(OH)2 is 0.077M

7 0

3 years ago

A certain liquid X has a normal boiling point of 111.20 celsius and a boiling point elevation constant Kb=0.95. calculate the bo

Goshia [24]

Answer: the boiling point is = 137.325°C

Explanation:

From the formula: ∆Tb= Kb*m

From the question, Kb= 0.95, m= 27.5, T1= 111.2°C

Substitute into ∆Tb= Kb*m

∆Tb= 0.95*27.5= 26.125

∆Tb= T2-T1

Hence

T2- 111.2=26.125

T2= 26.125+ 111.2= 137.325°C

8 0

3 years ago