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3 years ago

Which atom is used today as the standard for the atomic mass scale

Chemistry

1 answer:

igomit [66]3 years ago

3 0

Answer:Carbon

Explanation:

The carbon-12 atom, which is still used as the standard today, contains six protons and six neutrons for an atomic mass of twelve amu.

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What is the common name of this?

drek231 [11]

Answer:

butyl alcohol

Explanation:

8 0

3 years ago

Suppose of copper(II) acetate is dissolved in of a aqueous solution of sodium chromate. Calculate the final molarity of acetate

uranmaximum [27]

Answer:

0.0714 M for the given variables

Explanation:

The question is missing some data, but one of the original questions regarding this problem provides the following data:

Mass of copper(II) acetate: $m_{(AcO)_2Cu} = 0.972 g$

Volume of the sodium chromate solution: $V_{Na_2CrO_4} = 150.0 mL$

Molarity of the sodium chromate solution: $c_{Na_2CrO_4} = 0.0400 M$

Now, when copper(II) acetate reacts with sodium chromate, an insoluble copper(II) chromate is formed:

$(CH_3COO)_2Cu (aq) + Na_2CrO_4 (aq)\rightarrow 2 CH_3COONa (aq) + CuCrO_4 (s)$

Find moles of each reactant. or copper(II) acetate, divide its mass by the molar mass:

$n_{(AcO)_2Cu} = \frac{0.972 g}{181.63 g/mol} = 0.0053515 mol$

Moles of the sodium chromate solution would be found by multiplying its volume by molarity:

$n_{Na_2CrO_4} = 0.0400 M\cdot 0.1500 L = 0.00600 mol$

Find the limiting reactant. Notice that stoichiometry of this reaction is 1 : 1, so we can compare moles directly. Moles of copper(II) acetate are lower than moles of sodium chromate, so copper(II) acetate is our limiting reactant.

Write the net ionic equation for this reaction:

$Cu^{2+} (aq) + CrO_4^{2-} (aq)\rightarrow CuCrO_4 (s)$

Notice that acetate is the ion spectator. This means it doesn't react, its moles throughout reaction stay the same. We started with:

$n_{(AcO)_2Cu} = 0.0053515 mol$

According to stoichiometry, 1 unit of copper(II) acetate has 2 units of acetate, so moles of acetate are equal to:

$n_{AcO^-} = 2\cdot 0.0053515 mol = 0.010703 mol$

The total volume of this solution doesn't change, so dividing moles of acetate by this volume will yield the molarity of acetate:

$c_{AcO^-} = \frac{0.010703 mol}{0.1500 L} = 0.0714 M$

8 0

4 years ago

Dependent variable? ( what did we measore)?

lana66690 [7]

The thing u change.

6 0

3 years ago

Are all single bonds sigma bonds?

Nikolay [14]

Single bonds are those that bond with one atom, and sigma bonds are the strongest type of covalent bonds that are single bonded.

That means NO, not all single bonds are sigma bond, but all sigma bonds are single bonds.

6 0

3 years ago

1. When an ionic bond forms between magnesium (Mg) and bromine (Br), which of the following occurs?

AleksAgata [21]

The correct answers are:

1. B. Mg loses two electrons.

When Mg and Br combine, 2 atoms of Br attaches itself to Mg. The chemical reaction is:

Mg + Br ---> MgBr2

Since Br is more electronegative than Mg, then Mg loses an electron per Br therefore losing 2 electrons.

2. D. An atom that gains electrons must be attracted to an atom that loses electrons.

An ionic bond is formed when one molecule is more electronegative than the other molecule which results in gaining and losing of electrons. The more electronegative molecule gains electron while the less electronegative loses electron.

8 0

3 years ago