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nexus9112 [7]
3 years ago
8

Câu 12. Hiện tượng nào sau đây không phải là sự nóng chảy?

Chemistry
1 answer:
Alik [6]3 years ago
5 0
Mình nghĩ C là đáp án đúng
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g Suppose 0.0350 g M g is reacted with 10.00 mL of 6 M H C l to produce aqueous magnesium chloride and hydrogen gas. M g ( s ) +
iren2701 [21]

Answer:

Mg will be the limiting reagent.

Explanation:

The balanced reaction is:

Mg + 2 HCl → MgCl₂ + H₂

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

  • Mg: 1 mole
  • HCl: 2 moles
  • MgCl₂: 1 mole
  • H₂: 1 mole

Being the molar mass of each compound:

  • Mg: 24.3 g/mole
  • HCl: 36.45 g/mole
  • MgCl₂: 95.2 g/mole
  • H₂: 2 g/mole

By reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

  • Mg: 1 mole* 24.3 g/mole= 24.3 g
  • HCl: 2 moles* 36.45 g/mole= 72.9 g
  • MgCl₂: 1 mole* 95.2 g/mole= 95.2 g
  • H₂: 1 mole* 2 g/mole= 2 g

0.0350 g of Mg is reacted with 10.00 mL (equal to 0.01 L) of 6 M HCl.

Molarity being the number of moles of solute that are dissolved in a certain volume, expressed as:

Molarity=\frac{number of moles of solute}{volume}

in units \frac{moles}{liter}

then, the number of moles of HCl that react is:

6 M=\frac{number of moles of HCl}{0.01 L}

number of moles of HCl= 6 M*0.01 L

number of moles of HCl= 0.06 moles

Then you can apply the following rule of three: if by stoichiometry 2 moles of HCl react with 24.3 grams of Mg, 0.06 moles of HCl react with how much mass of Mg?

mass of Mg=\frac{0.06 moles of HCl* 24.3 grams of Mg}{2 moles of HCl}

mass of Mg= 0.729 grams

But 0.729 grams of Mg are not available, 0.0350 grams are available. Since you have less mass than you need to react with 0.06 moles of HCl, <u><em>Mg will be the limiting reagent.</em></u>

7 0
3 years ago
If you have 125 g of iron, how many grams of iron (iii)oxide will be formed
damaskus [11]

179.4 g will be formed from 123g of iron

5 0
3 years ago
A medicine is given 73 grains ap/lbs. of patient per dose. The patient weighs 65.7 kilograms. how many drams ap should the apoth
erastova [34]

10,573.4

Explanation:

Given parameters:

Dosage per patient = 73ap/lbs

Weight of patient = 65.7kg

Unknown:

Amount of grams/ap to be given to the patient;

 

Solution:

Since our final answer should be expressed in grams, let us convert all units into grams.

   1000g = 1kg

 Converting 65.7kg to g = 65.7 x 1000 = 65700g

73ap/lbs;

      1lb = 453.6g

 73ap/lbs x \frac{1lb}{453.6g} = 0.161ap/g

Now,

 For a 65700g person, the number of grains app required;

      65700 x 0.161 = 10,573.4grains ap per dose

learn more:

Mass brainly.com/question/3764212

#learnwithBrainly

3 0
3 years ago
Consider the reaction. How many grams of carbon should be burned in an excess of oxygen at STP to obtain 2.21 L of carbon dioxid
MissTica

You must burn 1.17 g C to obtain 2.21 L CO₂ at STP.

The balanced chemical equation is

C + O₂ → CO₂.

<em>Step 1</em>. Convert <em>litres of CO₂ to moles of CO₂</em>.

STP is <em>0 °C and 1 bar</em>. At STP the volume of 1 mol of an ideal gas is 22.71 L.

Moles of CO₂ = 2.21 L CO₂ × (1 mol CO₂/22.71 L CO₂) = 0.097 31 mol CO₂

<em>Step 2</em>. Use the molar ratio of C:CO₂ to <em>convert moles of CO₂ to moles of C </em>

Moles of C = 0.097 31mol CO₂ × (1 mol C/1 mol CO₂) = 0.097 31mol C

<em>Step 3</em>. Use the molar mass of C to <em>calculate the mass of C </em>

Mass of C = 0.097 31mol C × (12.01 g C/1 mol C) = 1.17 g C

It looks as if you are using the <em>old (pre-1982) definition</em> of STP. That definition gives a value of 1.18 g C.

8 0
3 years ago
Read 2 more answers
Balance the following chemical equation (if necessary) for the synthesis of aspirin from salicylic acid and acetic anhydride sho
labwork [276]

\\ \tt\rightarrowtail C_7H_6O_3+C_4H6O_3\longrightarrow C_9H_8O_4+C_2H_4O_2

It's already balanced

On both sides

  • C=11
  • H=12
  • O=6
5 0
2 years ago
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