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3 years ago

4Cuo - 2Cu,O + O, AH = 288 kJ

Chemistry

1 answer:

Anna35 [415]3 years ago

6 0

I am a little slow i cannot help with these that why i got this app lol

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Write the balanced equation for the reaction of aqueous Pb ( ClO 3 ) 2 with aqueous NaI . Include phases. chemical equation: Wha

Citrus2011 [14]

<u>Answer:</u> The mass of lead iodide produced is 9.22 grams

<u>Explanation:</u>

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Molarity of NaI = 0.200 M

Volume of solution = 0.200 L

Putting values in above equation, we get:

$0.200M=\frac{\text{Moles of NaI}}{0.200}\\\\\text{Moles of NaI}=(0.200mol/L\times 0.200L)=0.04moles$

The chemical equation for the reaction of NaI and lead chlorate follows:

$Pb(ClO_3)_2(aq.)+2NaI(aq.)\rightarrow PbI_2(s)+2NaClO_3(aq.)$

By Stoichiometry of the reaction:

2 moles of NaI reacts produces 1 mole of lead iodide

So, 0.04 moles of NaI will react with = $\frac{1}{2}\times 0.04=0.02mol$ of lead iodide

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Molar mass of lead iodide = 461 g/mol

Moles of lead iodide= 0.02 moles

Putting values in above equation, we get:

$0.02mol=\frac{\text{Mass of lead iodide}}{461g/mol}\\\\\text{Mass of lead iodide}=(0.02mol\times 461g/mol)=9.22g$

Hence, the mass of lead iodide produced is 9.22 grams

6 0

3 years ago

When biological samples of unknown origins are discovered at a crime scene, what should investigators do?a. assume no pathogens

adoni [48]

Answer: assume pathogens are present and treat the samples accordingly

Explanation:

When investigators are unable to conclusively ascertain the source of a biological sample found at a crime scene, the correct thing to do is to treat it as if pathogens are present in it and handle it according to set rules on how to handle pathogens.

This is done to ensure that if a pathogen is indeed present, it would not cause a health emergency by infecting those who come in contact with the samples at the scene.

3 0

3 years ago

The noble gases are inert due to the fact that A. their valence shell is empty B. their valence shell is full C. their electrons

coldgirl [10]

Answer:

B) Their valence shell is full

Explanation:

In order to be classified as a noble gas, an element must have a complete octet/ a full shell of valence electrons, as shown in answer B.

A and C are just incorrect. Since noble gasses are very unstable, D is a true statement, but is isn't the correct answer as this does not explain why they are inert.

<h3>Hope this was helpful!</h3>

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3 years ago

What is the difference between osmosis and diffusion?

Scorpion4ik [409]

<span>B. Osmosis is movement of proteins, and diffusion is movement of water.
</span>

3 0

4 years ago

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Which of these would provide the best evidence for the theory of evolution?

Nikolay [14]

evolution is the change a species goes through

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3 years ago