The statement that people who exercise for an hour may have lower cholesterol levels is it a hypothesis, law, or observation?

Two Balloons one filled with hydrogen gas and second filled with neon gas. what gas should be used in an experiement to identify

dalvyx [7]

Answer:

Oxygen

Explanation:

If two balloons are filled with hydrogen gas and helium gas respectively, then we want to identify what gas is in each balloon, we have to do so by exposing the both balloons to flame in an oxygen atmosphere.

Hydrogen combines with oxygen in the presence of a flame with quite a loud sound and the flame is sustained but when a flame is brought near helium gas in a balloon, the gas will only make a little sound when exposed to the flame and extinguish the flame.

The reason for the explosion of the gas in the hydrogen balloon is that combustion of hydrogen gas is exothermic. The heating up of surrounding air molecules leads to a sudden explosion.

However, the helium balloon makes a little sound when the balloon is ruptured releasing helium gas which extinguishes the flame.

8 0

3 years ago

Help PLEASEEE !!!!!! will give brainliest !

BabaBlast [244]

Answer:

6. O₂ + Cu —> CuO

7. H₂ + Fe₂O₃ —> H₂O + Fe

8. O₂ + H₂ — > H₂O

9. H₂S + NaOH —> Na₂S + H₂O

10. Al + HCl —> H₂ + AlCl₃

Explanation:

6. Oxygen gas react with solid copper metal to form copper(II) oxide

Oxygen gas => O₂

Copper => Cu

copper(II) oxide => CuO

The equation is:

O₂ + Cu —> CuO

7. hydrogen gas and iron(III) oxide powder react to form liquid water and solid iron power

hydrogen gas => H₂

Iron(III) oxide => Fe₂O₃

Water => H₂O

Iron => Fe

The equation is:

H₂ + Fe₂O₃ —> H₂O + Fe

8. Oxygen gas react with hydrogen gas to form liquid water

Oxygen gas => O₂

hydrogen gas => H₂

Water => H₂O

The equation is:

O₂ + H₂ — > H₂O

9. Hydrogen sulphide gas is bubbled through a sodium hydroxide solution to produce sodium sulphide and liquid water

hydrogen sulphide => H₂S

sodium hydroxide => NaOH

Sodium sulphide => Na₂S

Water => H₂O

The equation is:

H₂S + NaOH —> Na₂S + H₂O

10. Hydrogen gas and aluminum chloride solutions are produced when solid aluminum react with hydrochloric acid

Aluminum => Al

Hydrochloric acid => HCl

hydrogen gas => H₂

Aluminum chloride => AlCl₃

The equation is:

Al + HCl —> H₂ + AlCl₃

5 0

3 years ago

Calculating molarity using solute moles A chemist prepares a solution of sodium chloride (NaCl) by measuring out 6.89 mol of sod

hram777 [196]

Answer: Concentration of the chemist's sodium chloride solution is 34.4 mol/L.

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

$Molarity=\frac{n\times 1000}{V_s}$

where,

n= moles of solute

$V_s$ = volume of solution in ml

Given : moles of $NaCl$ = 6.89

volume of solution = 200 ml

Putting in the values we get:

$Molarity=\frac{6.89\times 1000}{200}=34.4mol/L$

Thus the concentration of the chemist's sodium chloride solution is 34.4 mol/L.

7 0

3 years ago

19. What is sthe mass of 6.02 x 1024 atoms

alekssr [168]

The mass of magnesium in $6.02 \times 10^{24}$ atoms is 240 g.

Answer: Option A

<u>Explanation:</u>

First, we have to convert the atoms to moles of magnesium.

We know that $6.02 \times 10^{24}$ atoms are present in 1 mole of magnesium. So,

$\text { 1 atom }=\frac{1}{6.02 \times 10^{24}} \text { moles }$

$6.02 \times 10^{24} \text { atoms }=\frac{6.02 \times 10^{24}}{6.02 \times 10^{23}} \text { moles }=10 \text { moles }$

Thus,

$Mass of M g= molar mass of M g \times No. of moles of M g$

$\text { Mass of } M g=24 \times 10=240 g$

Thus, 240 g of Magnesium is present in $6.02 \times 10^{24}$ atoms.

4 0

3 years ago

Help!

podryga [215]

I’m pretty sure it’s 7.5 (7 and a half hours) sorry if i’m wrong

3 0

3 years ago