In each pair of statements, choose the example that is more reliable.

Chemistry

2 answers:

TEA [102]3 years ago

3 0

Answer:

"statement 2" for the first pair and "statement 1" for the second pair

Explanation:

BlessedZay2 years ago

0 0

In each pair of statements, choose the example that is more reliable.

Statement 1
The company Herbal Remedies Inc. announced today that its antiobesity skin treatment is safe and effective.

Statement 2
The US Food and Drug Administration (FDA) announced today that cancer treatment X, manufactured by Pharma Inc., is safe and effective.

Statement 1
An independent chemical analysis paid for by local residents determined that wells are contaminated with dioxin at a concentration of 3 ppb.

Statement 2
The chemical company Chemicals Inc. insists that local groundwater has not been affected adversely by a leak in its waste handling system.

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Balance the following equations: (c) H2(g)+I2(s)⟶HI(s)H2(g)+I2(s)⟶HI(s)

kenny6666 [7]

Answer: $H_2(g)+I_2(g)\rightarrow 2HI(s)$

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

Thus in the reactants, there are 2 atoms of hydrogen and 2 atoms of iodine .Thus there has to be 2 atoms of hydrogen and 2 atoms of iodine in the product as well. Thus a coefficient of 2 is placed in front of HI.

The balanced chemical reaction is:

$H_2(g)+I_2(g)\rightarrow 2HI(s)$

6 0

3 years ago

Given pH = 8.55 Find: [H3O+] and [OH-] Is this acidic, basic or neutral?

Firlakuza [10]

Answer:

Explanation:

The given pH = 8.55

Unknown:

[H₃O⁺] = ?

[OH⁻] = ?

In order to find these unknowns we must first establish some relationship.

pH = -log[H₃O⁺]

8.55 = -log[H₃O⁺]

[H₃O⁺] = inverse log₁₀(-8.55) = 2.82 x 10⁻⁹moldm⁻³

To find the [OH⁻],

pH + pOH = 14

pOH = 14 - pH = 14 - 8.55

pOH = 5.45

pOH = -log[OH⁻]

[OH⁻] = inverse log₁₀ (-5.45) = 3.55 x 10⁻⁶moldm⁻³

The solution is basic because it has more concentration of OH⁻ ions compared to H⁺ ions.

7 0

3 years ago

Which of the following is the requirement for the intramolecular Sn2 reaction (intramolecular William Ether Synthesis) to occur

balandron [24]

Answer:

D. Anti-periplanar

Explanation:

In the second step of the intramolecular William Ether Synthesis mechanism (figure 1) we will have the attack of the negative charge of the oxygen to the carbon bond to the Br. At the same time the Br leaves, so a bond would be broken (the C-Br bond) and a bond would be formed (the C-O bond).

Now, this process can happen only if the attack and the leaving group has an anti configuration (figure 2). In an anti configuration the nucleophile and the leaving group would have opposite directions.