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3 years ago

Please help with this questio

Chemistry

2 answers:

MAXImum [283]3 years ago

8 0

Answer:

you didnt give the question

Explanation:

fredd [130]3 years ago

8 0

Answer:

What he said☝️

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29. What is E for a system which has the following two steps:

jasenka [17]

Answer:

Zero

Explanation:

Recall that;

E = q + w

Where;

q = heat, w = work done

When heat is absorbed by the system q is positive

When heat is evolved by the system q is negative

When the system does work, w is negative

When work is done on the system w is positive

Step 1

ΔE1= 60 KJ + 40 KJ = 100KJ

Step 2

ΔE2= (-30 KJ) + (-70 KJ) = (-100) KJ

ΔE1 + ΔE2= 100KJ + (-100) KJ = 0KJ

4 0

3 years ago

Be able to identify the correct elements using clues such as numbers of protons,locations (family/period), number of neutrons, n

Brilliant_brown [7]

an element's name, chemical symbol, atomic number, atomic mass.

IDK what you are even asking for

6 0

3 years ago

I in the blanks.<br>The solid substance left on the filter paper is called

horsena [70]

Explanation:

the solid substance which left on the filter paper is called Residue

3 0

3 years ago

CaO + H2O -> Ca(OH)2

yawa3891 [41]

The % yield of Ca(OH)₂ : 62.98%

<h3>Further eplanation </h3>

Percent yield is the compare of the amount of product obtained from a reaction with the amount you calculated

General formula:

Percent yield = (Actual yield / theoretical yield )x 100%

An actual yield is the amount of product actually produced by the reaction. A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients

Reaction

CaO + H₂O ⇒ Ca(OH)₂

mass CaO= 4.2 g

mol CaO(MW=56,0774 g/mol) :

$\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{4.2}{56,0774 g/mol}\\\\mol=0.075$

mol Ca(OH)₂ based on mol CaO

mol ratio CaO : Ca(OH)₂,= 1 : 1, so mol Ca(OH)₂ = 0.075

mass Ca(OH)₂(MW=74,093 g/mol) ⇒ theoretical

$\tt mass=mol\times MW\\\\mass=0.075\times 74,093 g/mol\\\\mass=5.557~g$

% yield :

$\tt =\dfrac{actual}{theoretical}\times 100\%\\\\=\dfrac{3.5}{5.557}\times 100\%\\\\=62.98\%$

8 0

3 years ago

If it 1:40 then what time will it be in 3 hours and 20 minutes

Dominik [7]

In three hours and twenty minutes from 1:40 will be 5:00

6 0

3 years ago

Read 2 more answers