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3 years ago

Please help this is on my exam

Chemistry

1 answer:

Vikentia [17]3 years ago

6 0

Answer:

D. The time of day

Explanation:

The independent variable is the variable the experimenter changes or controls and is assumed to have a direct effect on the dependent variable

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Emily spills concentrated sodium hydroxide solution on her lab bench. What she should do first?

blagie [28]

<h2>Answer:</h2>

She should notify her teacher.

<h2>Explanation:</h2>

Sodium Hydroxide is very corrosive in nature and it causes Redness, Pain, Serious skin burns and Blisters. Sodium hydroxide does not produce systemic toxicity, but is very CORROSIVE and can cause severe burns in all tissues that it comes in contact with. Therefore she should not touch it and she must notify her teacher as soon as possible.

4 0

3 years ago

Calculate the average reaction rate expressed in moles h2 consumed per liter per second

djyliett [7]

Answer:

Average rate of reaction expressed in moles H₂ consumed per liter per second = 0.0025 M/s = 0.0025 mol/L.s

Explanation:

The complete, correct Question, is presented in the attached image to this answer.

The average rate of reaction in terms of the reactant is defined as the total amount of reactant consumed over a period of time divided by total period of time.

Mathematically,

Average rate of reaction = (change in concentration of H₂ over a period of time) ÷ (total period of time)

Average rate of reaction = (-ΔC)/(Δt)

The minus sign is there because the concentration of reactants reduce with time.

change in concentration of H₂ = -ΔC

= -(0.02 - 0.03) = 0.01 M

Time = Δt = 4 - 0 = 4.0 s

Average rate of reaction = (0.01/4) = 0.0025 M/s

We could solve for the average rate of reaction expressed in moles Cl₂ consumed per liter per second

change in concentration of Cl₂ = -ΔC

= -(0.04 - 0.05) = 0.01 M

Time = Δt = 4 - 0 = 4.0 s

Average rate of reaction = (0.01/4) = 0.0025 M/s = 0.0025 mol/L.s

Hope this Helps!!!

8 0

4 years ago

Consider the following scenario

GarryVolchara [31]

Answer:

See explaination

Explanation:

Going by the clues that it is between Silver Flouride (AgF) and Sodium Fluoride (NaF) and since it is an aqueous solution , the 1 liter bottle is likely to be Sodium Chloride( NaCl). Going by the reaction,

AgF + NaCl= AgCl + NaF

Here, the color of AgCl is white, hence the solution cannot be AgCl.

Determination of NaCl

Determination of NaCl can be done by Mohr's Method or Volhard's method. But results in Volhard's method are more accurate . Its uses the method of back titration with Potassium Thiocynate which forms a AgCl precipitate . Prior to titration,excess AgNO3 ( The problem also has a clue that excess reagents are present in the lab ) is added to the NaCl solution so that all the Cl- ions react with Ag+. Fe3+ is then added as an indicator and the solution is titrated with KSCN to form a silver thiocyannite precipitate (AgSCN). Once all the silver has reacted, a slight excess of SCN- reacts with Fe3+ to form Fe(SCN)3 dark red complex. The concentration of Cl- is determined by subtracting the titer findings of Ag+ ions that reacted to form AgSCN from the Ag NO3 moles added to the solution. This is used because pH of the solution is acidic. If the pH of solution is basic, Mohr's method is used.

Reactions

Ag+ (aq)+ Cl-(aq) = AgCl(aq)

Ag+(aq) + SCN-(aq) = AgSCN(aq)

Fe3+(aq) + SCN-(aq) = [FeSCN]2- (aq)

7 0

4 years ago

WILL MARK YOU THE BRAINLIEST IF YOU ANSWER THESE TWO QUESTION CORRECTLY :)

lara [203]

Answer: 1. HYDROCARBONS? 2. ALKANES?

i'm not exactly AMAZING at this but i did some research and this is what i think it is i'm also not in this grade but i tried.

7 0

3 years ago

How many molecules are in 13 moles of oxygen?

natima [27]

Answer:

mass/13of molecules .........

8 0

3 years ago

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