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3 years ago

Explică rolul chimiei în protejarea mediului înconjurător?

Chemistry

1 answer:

Degger [83]3 years ago

6 0

Answer:

Chimia ne poate ajuta să înțelegem, monitorizăm, protejăm și îmbunătățim mediul din jurul nostru. Chimiștii dezvoltă instrumente și tehnici pentru a ne asigura că putem vedea și măsura poluarea aerului și a apei.

Explanation: I speak english i just know Romanian language

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A solution that has a large amount of dissolved solute is called

kvasek [131]

Answer: It is an unsaturated solution

Explanation: This is because it has more solute than a normal solution.

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3 years ago

What is wrong with this graph? * 1 point 7 6- 2 0

snow_lady [41]

Answer:

The Red?

Explanation:

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3 years ago

Read 2 more answers

How many Joules are released to cool 250.0 grams of liquid water from 100°C to 0°C? The specific heat of water is 4.180 J/g.C.

nlexa [21]

$\bold{\huge{\orange{\underline{ Solution}}}}$

$\bold{\underline{ Given :- }}$

We have 250g of liquid water and it needs to be cool at temperature from 100° C to 0° C
Specific heat of water is 4.180J/g°C

$\bold{\underline{ To \: Find :- }}$

We have to find the total number of joules released.

$\bold{\underline{ Let's \:Begin:- }}$

We know that,

Amount of heat energy = mass * specific heat * change in temperature

That is, 

$\sf{\red{ Q = mcΔT }}$

Subsitute the required values in the above formula :-

$\sf{ Q = 250 × 4.180 ×(0 - 100 )}$

$\sf{ Q = 250 × 4.180 × - 100 }$

$\sf{ Q = 250 × - 418}$

$\sf{\pink{ Q = - 104,500 J }}$

Hence, 104,500 J of heat is released to cool 250 grams of liquid water from 100° C to 0° C.

$\bold{\underline{ Now :- }}$

We have to tell whether the above process is endothermic or exothermic :-

Here, In the above process ΔT is negative and as a result of it Q is also negative that means above process is Exothermic

Exothermic process :- It is the process in which heat is evolved .
Endothermic process :- It is the process in which heat is absorbed .

4 0

2 years ago

With 21 g of Zinc, and 7 g of CuCl2, how much ZnCl2 is made in grams?

mina [271]

Answer: 7.07 grams

Explanation:

To calculate the moles :

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

$\text{Moles of} zinc=\frac{21g}{65g/mol}=0.32moles$

$\text{Moles of} CuCl_2=\frac{7g}{134g/mol}=0.052moles$

$Zn+CuCl_2\rightarrow Cu+ZnCl_2$

According to stoichiometry :

1 mole of $CuCl_2$ require 1 mole of $Zn$

Thus 0.052 moles of $CuCl_2$ will require= $\frac{1}{1}\times 0.052=0.052moles$ of $Zn$

Thus $CuCl_2$ is the limiting reagent as it limits the formation of product and $Zn$ is the excess reagent.

As 1 mole of $CuCl_2$ give = 1 mole of $ZnCl_2$

Thus 0.052 moles of $CuCl_2$ give = $\frac{1}{1}\times 0.052=0.052moles$ of $ZnCl_2$

Mass of $ZnCl_2=moles\times {\text {Molar mass}}=0.052moles\times 136g/mol=7.07g$

Thus 7.07 g of $ZnCl_2$ will be produced from the given masses of both reactants.

8 0

3 years ago

When testing to see how water affects plant growth, John make sure one set of his plants does not get water. This set of plants

Mashcka [7]

Answer:

control.

Explanation:

during an experiment you are required to maintain a separate group of subjects to collect data on so you will be able to make comparisons from your observations. assuming the watered plants grew, what does that mean? they grew at a quicker rate? slower rate? the same rate? compared to what? you need this control group in order to prove your observations either one way or the other such as "compared to unwatered plants, the watered plants grew at *blank* rate."

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3 years ago