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2 years ago

What is an element considered a pure substance?

1 answer:

8 0

A compound is a pure substance composed of two or more different atoms chemically bonded to one another. A compound can be destroyed by chemical means. It might be broken down into simpler compounds, into its elements or a combination of the two.

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Convert 5.4g of NaCl to moles

sammy [17]

Answer:

.0924 moles of NaCl

Explanation:

So you know you have 5.4 g of NaCl and you need to know how many moles there are in this amount of NaCl

You'll need to find the atomic mass of the compound NaCl to help you solve for moles

Sodium (Na) on the periodic table has a mass of 22.99

Chlorine (Cl) on the periodic table has a mass of 35.45

Add these two together----> 22.99 + 35.45 = 58.44

Now you can calculate for moles

Written-out method:

5.4 grams of NaCl | 1 mole of NaCl

| 58.44 grams NaCl = .0924 moles of NaCl

Plug into calculator method:

(5.4 g of NaCl/ 58.44g NaCl= .0925 moles)

7 0

2 years ago

A sample of propane(c3h8)has 3.84x10^24 H atoms.

deff fn [24]

Answer:

A) 14. 25 × 10²³ Carbon atoms

B) 34.72 grams

Explanation:

1 molecule of Propane has 3 atoms of Carbon and 8 atoms of Hydrogen.

The sample has 3.84 × 10²⁴ H atoms.

If 8 atoms of Hydrogrn are present in 1 molecule of propane.

3.84 × 10²⁴ H atoms are present in

$\mathfrak{ \frac{3.8 }{8} \times 10 ^{24}}$

= 4.75 × 10²³ molecules of Propane.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

No. of Carbon atoms in 1 molecule of propane = 3

=> C atoms in 4.75× 10²³ molecules of Propane = 3 × 4.75 × 10²³

= 14.25 × 10²³ 

________________________________________

Gram Molecular Mass of Propane(C3H8)

= 3 × 12 + 8 × 1

= 36 + 8

= 44 g

1 mole of propane weighs 44g and has 6.02× 10²³ molecules of Propane.

=> 6.02 × 10²³ molecules of Propane weigh = 44 g

=> 4. 75 × 10²³ molecules of Propane weigh =

$\mathsf{ \frac{44 }{6.02 \times {10}^{23} } \times 4.75 \times {10}^{23} }$

$\mathsf{ = \frac{44 }{6.02 \times \cancel{{10}^{23} }} \times 4.75 \times \cancel{ {10}^{23}} }$

$\mathsf{ = \frac{44 }{6.02 } \times 4.75 }$

= 34.72 g

8 0

2 years ago

Even if you don't touch a marshmallow to a campfire flame, holding a marshmallow near a flame causes it to toast and turn brown.

Olin [163]

Heat radiates from the fire and cooks the marshmallow because heat transfer.

6 0

2 years ago

Read 2 more answers

How fast do i have to run 250 m in 30 seconds

elena-14-01-66 [18.8K]

Answer:

S=D/T

250/30= 8.33 miles

Explanation:

7 0

2 years ago

In a double-blind test, the non-control group receives a

Aleksandr [31]

Answer:

Hi There! I'm new so I hope I get This Right! ^^

Explanation:

double blind test. the control group receives a placebo. Why is a placebo used in a double-blind test? so that the effects on people in two different groups can be compared.

happy To Help! ^^

6 0

3 years ago