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Vaselesa [24]
3 years ago
11

PLEASE HELP I really need someone to answer this!!!!

Chemistry
2 answers:
marshall27 [118]3 years ago
6 0

Answer: I think it’s the first one

Molodets [167]3 years ago
4 0
the first one with the penny in vinegar :)
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Which equation represents a redox reaction?
labwork [276]

Answer:

D. 2NaBr + Cl_2\rightarrow 2NaCl + Br_2

Explanation:

Hello!

In this case, for the given set of chemical reactions, it is possible to infer that D. is a categorized as redox due to the following:

Since both chlorine and bromine remain as diatomic gases, their oxidation states in such a form is 0, but as anions with lithium cations they have a charge of - according to the following reaction and half-reactions:

2NaBr + Cl_2\rightarrow 2NaCl + Br_2

Cl_2^0+2e^-\rightarrow 2Cl ^-\\\\2Br^- \rightarrow  Br_2^0+2e^-

Unlike the other reactions whereas no change in the oxidation states is evidenced.

6 0
3 years ago
Read 2 more answers
A 25.00-mL aliquot of a nitric acid solution of unknown concentration is pipetted into a 125-mL Erlenmeyer flask and 2 drops of
Semenov [28]

Answer:

0.0611M of HNO3

Explanation:

<em>The concentration of the NaOH solution must be 0.1198M</em>

<em />

The reaction of NaOH with HNO3 is:

NaOH + HNO3 → NaNO3 + H2O

<em>1 mole of NaOH reacts per mole of HNO3.</em>

That means the moles of NaOH used in the titration are equal to moles of HNO3.

<em>Moles HNO3:</em>

12.75mL = 0.01275L * (0.1198mol / L) = 0.0015274 moles NaOH = Moles HNO3.

In 25.00mL = 0.025L -The volume of the aliquot-:

0.00153 moles HNO3 / 0.025L =

<h3> 0.0611M of HNO3</h3>
7 0
3 years ago
If you know the mass of Earth, what other single value would you need to know to calculate Earth's average density?
Dennis_Churaev [7]

Answer:

Volume

Explanation:

Density:

Density is equal to the mass of substance divided by its volume.  In order to find the density of earth when mass is given we have to calculate its volume. The volume of earth is calculated by using the volume formula for sphere. i.e 4/3 π r³. we also require radius to find the volume and we know that

Diameter = 2 × radius

The diameter of earth equator is 12756.75 Km. So we calculate the radius by dividing the diameter by 2. Then by putting the value of radius in 4/3 π r³ we will get the volume and then we can calculate the density of earth.

Units:

SI unit of density is Kg/m3.

Other units are given below,

g/cm3, g/mL , kg/L

Formula:

D=m/v

D= density

m=mass

V=volume

Symbol:

The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.

7 0
3 years ago
72.40% iron,27.60% Oxygen Empirical formula
VARVARA [1.3K]

Explanation:

Fe. O

72.40/ 56 27.60/16

____________________

1.29/1.29 1.725/1.29

_____________________

1. :. 1

<h3>Emperical formula = FeO</h3>
6 0
3 years ago
Which type of society survives mainly by foraging for food?
Dennis_Churaev [7]
The appropriate answer is a. HUNTER-GATHERER. Hunter-gatherer societies are nomadic and they forage for edible plants, bean, fruits and nuts. They also hunt wild game for food. Early humans in the Neolithic period practiced this way of life. 
Agrarian societies thrive on agriculture which they depend on for sustainable and for trade. Animals and plants are domesticated and so people can settle and build a society. Pastoral agriculture is a semi-nomadic lifestyle where the society is centered around keeping herds of grazing animals. Industrial societies focus on manufacturing and this is the backbone of the society. 
6 0
3 years ago
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