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3 years ago

Elle wanted to test how temperature affects the rate of evaporation. She had three setups:

Chemistry

1 answer:

Pie3 years ago

5 0

Answer:

Temperature

Explanation:

Here the factor that Elle is controlling is the temperature. So temperature here is the independent variable and the dependent variable is the rate of evaporation of water. Independent variable is controlled during the experiment setup and the outcome of the dependent variable depends on the independent variable.

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In the disproportionation reaction CI2 + H2Omc021-1.jpgHCIO + HCI, what describes the oxidation states of the substance Cl?

Sophie [7]

Reaction: CI2 + H2O ----> HCIO + HCI

Oxidations states:

The oxitation state of Cl2 = 0, because the oxidation state of an atom alone or a molucule with one kind of atom is always 0.

The oxidation state of Cl in HClO is +1 because the oxidation state of H is + 1, the oxidation state of O is - 2, and the molecule is neutral, so +1 + 1 - 2 = 0

The oxidation state of Cl in HCl is - 1, because the oxidation state of H is +1 and the molecule is neutral, so - 1 + 1 = 0.

Also, you shall remember that when an atom increases its oxidation state is is oxidized and when an atoms reduces its oxidations state it is reduced.

With that you conclude that the right option is the last statement: Cl has an oxidation number of 0 in Cl2. It is then reduced to CI- with an oxidation number of –1 in HCl and is oxidized to Cl+ with an oxidation number +1 in HClO.

8 0

4 years ago

Suppose 0.795 g of sodium iodide is dissolved in 100. mL of a 39.0 m M aqueous solution of silver nitrate.

lubasha [3.4K]

Answer:

The final molarity of iodide anion is 0.053 M

Explanation:

Step 1: Data given

Mass of sodium iodide (NaI) = 0.795 grams

Volume of the solution = 100 mL = 0.1 L

Molarity of aqueous solution of silver nitrate (AgNO3) = 39 mM = 0.039M

The molecular mass of sodium iodide is 149.89 g/mol.

Step 2: The balanced equation

AgNO3(aq) + NaI(aq) → AgI(s) + NaNO3(aq)

Step 3: Calculate number of moles of sodium iodide

Moles NaI = mass NaI / Molar mass NaI

Moles NaI = 0.795 grams / 149.89 g/mol

Moles NaI = 0.0053 moles

For 1 mole AgNO3 consumed, we need 1 mole NaI to produce 1 mole AgI and 1 mole NaNO3

The sodium iodide will dissociate as followed:

NaI(aq) → Na+(aq) + I-(aq)

Step 4: Calculate iodide ions

For 1 mole NaI, we have 1 mole of I-

For 0.0053 moles of NaI we'll have 0.0053 moles I-

Step 5: Calculate molarity of iodide ion

Molarity = moles I- / volume

Molarity I- = 0.0053 moles / 0.1 L

Molarity I- = 0.053 M

The final molarity of iodide anion is 0.053 M

5 0

3 years ago

In periodic table, valance electrons are indicated by

inn [45]

Valence electrons of elements except the transition elements – the main group elements. While the period number indicates the number of shells, the group number indicates the number of valence electrons in the outermost shell. Specifically, the number in the ones' place. It can never be replaced rarely anyways.

6 0

3 years ago

Ethanol (CH3CH2OH) is the alcohol found in beverages. It is oxidized in the body to

Marizza181 [45]

Answer:

B) Ethanol must act as a competitive inhibitor for the alcohol dehydrogenase and therefore slows the formation of formaldehyde.

Explanation:

An inhibitor is a substance that binds to an enzime and prevents it to react with a substrate. In this case, the inhibitor is ethanol, binding to the enzime (alcohol dehydrogenase) and preventing it to react with methanol and thus from it form the toxic formaldehyde.

A competitive inhibitor has a similar structure to the substrate, that is why it binds to the same active site. In this case, ethanol has a similar structure to methanol, which is why the answer is B and not A.

7 0

3 years ago

Which of the following metals has the highest melting point?

AveGali [126]

The metal with the highest melting point is aluminium which melts at 660.3°C.

Magnesium melts at 639°C , sodium at 98°C and potassium at 64°C.

The melting point is the temperature at which a substance begins to melt. As a solid substance is heated, or absorbs heat from the environment, the molecules that make up that substance begin to gain more (heat) energy, enough to overcome the intermolecular forces that in the first place have been holding them together in a sort of rigid fashion.

This energy enables the molecules to break free of their intermolecular forces and thus the solid's lattice structure changes and the solid becomes liquid.

3 0

4 years ago