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3 years ago

1. What is uncertainty in measurements?

Chemistry

1 answer:

Alex_Xolod [135]3 years ago

8 0

Answer:

In metrology, measurement uncertainty is the expression of the statistical dispersion of the values attributed to a measured quantity.By international agreement, this uncertainty has a probabilistic basis and reflects incomplete knowledge of the quantity value. It is a non-negative parameter.

<h2>Hope it helps you.</h2>

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Manganese commonly occurs in nature as a mineral. The extraction of manganese from the carbonite mineral rhodochrosite, involves

hjlf

This is an incomplete question, here is a complete question.

Manganese commonly occurs in nature as a mineral. The extraction of manganese from the carbonite mineral rhodochrosite, involves a two-step process. In the first step, manganese (II) carbonate and oxygen react to form manganese (IV) oxide and carbon dioxide:

$2MnCO_3(s)+O_2(g)\rightarrow 2MnO_2(s)+2CO_2(g)$

In the second step, manganese (IV) oxide and aluminum react to form manganese and aluminum oxide:

$3MnO_2(s)+4Al(s)\rightarrow 3Mn(s)+2Al_2O_3(s)$

Write the net chemical equation for the production of manganese from manganese (II) carbonate, oxygen and aluminum. Be sure your equation is balanced.

Answer : The net chemical equation for the production of manganese is:

$6MnCO_3(s)+3O_2(g)+8Al(s)\rightarrow 6CO_2(g)+6Mn(s)+4Al_2O_3(s)$

Explanation :

The given two chemical reactions are:

(1) $2MnCO_3(s)+O_2(g)\rightarrow 2MnO_2(s)+2CO_2(g)$

(2) $3MnO_2(s)+4Al(s)\rightarrow 3Mn(s)+2Al_2O_3(s)$

First we are multiplying reaction 1 by 3, and reaction 2 by 2, we get:

(1)

(2) $6MnO_2(s)+8Al(s)\rightarrow 6Mn(s)+4Al_2O_3(s)$

Now we are adding both the reactions, we get the overall chemical reaction.

$6MnCO_3(s)+3O_2(g)+6MnO_2(s)+8Al(s)\rightarrow 6MnO_2(s)+6CO_2(g)+6Mn(s)+4Al_2O_3(s)$

The $MnO_2$ is common on both side, by cancelling it, we get:

The net chemical equation for the production of manganese is:

$6MnCO_3(s)+3O_2(g)+8Al(s)\rightarrow 6CO_2(g)+6Mn(s)+4Al_2O_3(s)$

5 0

4 years ago

Compound A, C7H13Br, is a tertiary alkyl bromide. On treatment with CH3CH2ONa, A is converted into B, C7H12. Ozonolysis of B wit

blsea [12.9K]

Answer:

Compound A: 1-bromo-1-methylcyclohexane

Compound B: 1-methylcyclohex-1-ene

Explanation:

In this question, we can start with the I.D.H (hydrogen deficiency index):

$I.D.H~=~\frac{(2C)+2+(N)-(H)-(X)}{2}$

In the formula we have 7 carbons, 13 hydrogens, and 1 Br, so:

$I.D.H~=~\frac{(2*7)+2+(0)-(13)-(1)}{2}=1$

We have an I.D.H value of one. This indicates that we can have a cyclic structure or a double bond.

We have to keep in mind that the Br atom must be bonded to a tertiary carbon. We can not have a double bond because in the ozonolysis reaction we have only 1 product, therefore, we can not have a double bond in the initial molecule (if we have a double bond in the initial molecule we will have more than 1 product in the ozonolysis reaction).

With this in mind, we will have a cyclic structure. If we have 7 carbons and we need a tertiary alkyl halide. We can have a cyclic structure of 6 members and a methyl group bonded to a carbon that also is bonded to a Br atom (1-bromo-1-methylcyclohexane).

In the reaction with $CH_3CH_2ONa$ we will have an elimination reaction. In other words, we have the production of a double bond inside of the cyclic structure (1-methylcyclohex-1-ene).

See figure 1 for further explanations.

I hope it helps!

8 0

3 years ago

What kind of charge would the oxygen atom have compared to the hydrogen atoms

Oliga [24]

It should be charge 2-they lose electrons

8 0

4 years ago

What is the mass of a dolphin swimming at 16 m/s with a momentum of 800 kg m/s?

REY [17]

Answer: 50 kg

Explanation: formula is

m= p/v

m=800 kg m/s : 16m/s

m= 50kg

idk tho hope this helps

8 0

3 years ago

Identify the elemant that is a nonmetal , a gas, and has an element symbol that starts with the letter a

lukranit [14]

The element that is a nonmetal, a gas, and has an element symbol that starts with the letter a is Ar (Argon).
Element Ar (Argon) is the third member of noble gases, in period 8, and makes up about 1% of the Earth's atmosphere. It has approximately the same solubility as oxygen and it is 2.5 times as soluble in water as nitrogen. It is an inert element that is colorless and odorless in both its liquid and gaseous forms.

6 0

4 years ago