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2 years ago

When planning a simple experiment, what does it mean to “test one variable”?

Chemistry

1 answer:

SSSSS [86.1K]2 years ago

3 0

Answer:

I believe the answer is "b". "During the experiment, the scientist has only one element, or variable, that is changed to test the hypothesis."

Explanation:

I remember from last year but I'm not totally sure. Good luck!

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If gravity ceased to exist on Earth, what would happen to our life supporting atmosphere ?

melamori03 [73]

C is correct. right now gravity holds the atmosphere so if there is no gravity then no atmospher

4 0

3 years ago

Using the balanced equation given below, calculate the number of moles of CaBr2 produced in the reaction of 5.0 moles of AlBr3.

allochka39001 [22]

Answer:

7.5 moles of CaBr2 are produced

Explanation:

Based on the equation:

2AlBr3 + 3CaO → Al2O3 + 3CaBr2

<em>2 moles of AlBr3 produce 3 moles of CaBr2 if CaO is in excess.</em>

<em />

Using this ratio: 2 moles AlBr3 / 3 moles CaBr2. 5 moles of AlBr3 produce:

5 moles AlBr3 * (3 moles CaBr2 / 2 moles AlBr3) =

<h3>7.5 moles of CaBr2 are produced</h3>

<em />

4 0

2 years ago

Write the net ionic equation for the reaction between hydrochloric acid and potassium cyanide. Do not include states such as (aq

zhannawk [14.2K]

Answer: $H^++CN^-\rightarrow HCN$ , product favoured

Explanation:

Complete ionic equation : In complete ionic equation, all the substance that are strong electrolyte and present in an aqueous are represented in the form of ions.

Net ionic equation : In the net ionic equations, we do not include the spectator ions in the equations.

When hydrochloric acid react with potassium cyanide, then it gives potassium chloride and hydrocyanic acid as products.

The complete ionic equation will be:

$H^++Cl^-+K^++CN^-\rightarrow K^++Cl^-+HCN$

The net ionic equation will not contain spectator ions which are $K^+$ and $Cl^-$ :

$H^++CN^-\rightarrow HCN$

The reaction is product favoured.

5 0

3 years ago

5.If 30mL of 0.5M NaOH(aq) was used to neutralize 10mL of HCl(aq), what is the concentration of the acid? Show work.

Zolol [24]

Answer:

0.15M

Explanation:

NaOH + HCl -->NaCl + H2O

moles of NaOH reacted with HCl

(0.5 × 30)/1000 = 1.5 × 10^ -3

so the moles of HCl reacted with NaOH

1.5 × 10^ -3

concentration of HCl = ( 1.5 × 10^ -3)/10 ×1000

7 0

3 years ago

List all orbitals from 1s through 5s according to increasing energy for multielectron atoms. Rank orbitals from smallest to larg

Paha777 [63]

Answer:

The given list of orbitals can be ranked as follow:

1s 2s 2p 3s 3p 4s 3d 4p 5s.

Explanation:

The given list of orbitals can be ranked as follow:

1s 2s 2p 3s 3p 4s 3d 4p 5s.

According to the Aufbau principal in ground state of elements electron first occupy the lower energy level then fill the higher energy levels. We know that there four subshells s, p, d and f. The maximum number of electrons in these subshells can be calculated by following formula:

2 (2l +1 )

and l = 0,1,2,3,....

maximum numbers of electrons in s subshell are,

l=0

2 ( 2(0) + 1)

so maximum electrons in s subshell are 2.

maximum numbers of electrons in p subshell are,

l = 1

2 ( 2(1) + 1)

2( 2 + 1

so maximum electrons in p subshell are 6.

maximum numbers of electrons in d subshell are,

l = 2

2 ( 2(2) + 1)

2( 4 + 1)

so maximum electrons in d subshell are 10.

maximum numbers of electrons in f subshell are,

l = 3

2 ( 2(3) + 1)

2( 6 + 1)

so maximum electrons in f subshell are 14.

Electron first fill 1s subshell then 2s subshell and in this way they goes to higher energy levels.

3 0

3 years ago