Provide the structure of the cyanohydrin that results when cyclopentanone reacts with hcn.

Which of the following describes the location and energy of all the valence electrons

Nastasia [14]

Answer:

1s22s22p6<u>3s23p4</u>

Explanation:

Sulfur is located in the p block and has 6 valence electrons (the 2 exponent on the 3s and the 4 exponent on the 3p add up to 6)

4 0

2 years ago

Strontium-90 is a radioisotope that will decrease in mass by one-half every 29 years. How many years will it take for a 10.0-gra

Lelechka [254]

Answer: It will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams

Explanation:

Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

Half life is represented by $t_{\frac{1}{2}$

$t_{\frac{1}{2}=\frac{0.693}{\lambda}$

$\lambda$ = rate constant

Given : Strontium-90 decreases in mass by one-half every 29 years , that is half life of Strontium-90 is 29 years.

As half life is independent of initial concentration, it will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams as the amount gets half.

7 0

3 years ago

The reaction in which methane is burned, CH4 +202 --> 2H20 + CO2, is an example of a

alexira [117]

Answer: Combustion

Explanation:

Methane gas or natural gas is the hydrocarbon that reacts with oxygen as shown below: CH4 + 2O2 → CO2 + 2H2O There are two types of combustion reactions: complete and incomplete combustion. Therefore there are four products, carbon dioxide, water, carbon, and carbon monoxide.

8 0

3 years ago

if the mass of 191 grams NaCl reacted with 74 frams of calcium hydroxide and 80 grams of sodium hydroxide is produced, what mass

nadya68 [22]

<h3>Answer:</h3>

110.98 g/mol

<h3>Explanation:</h3>

The reaction between NaCl and Ca(OH)₂ is given by the equation;

2NaCl(aq) + Ca(OH)₂(s) → 2NaOH(aq) + CaCl₂(aq)

We are required to determine the mass of CaCl₂ produced,

We will use the following simple steps;

Step 1: Moles of NaCl and Ca(OH)₂ given

Number of moles = Mass ÷ Molar mass

Moles of NaCl

Mass of NaCl = 191 g

Molar mass NaCl = 58.44 g/mol

Number of moles = 191 g ÷ 58.44 g/mol

= 3.268 moles

= 3.27 Moles

Moles of Ca(OH)₂

Mass of Ca(OH)₂ = 74 g

Molar mass of Ca(OH)₂ = 74.093 g/mol

Number of moles = 74 g ÷ 74.093 g/mol

= 0.998 mole

= 1.0 mole

However, from the equation 2 moles of NaCl requires 1 mole of Ca(OH)₂

Therefore, from the amount of reactants available NaCl was in excess and Ca(OH)₂ is the limiting reactant .

Step 2: Moles of CaCl₂ produced

From the equation

1 mole of Ca(OH)₂ reacts with NaCl to produce 1 mole of CaCl₂

Therefore; the mole ratio of Ca(OH)₂ to CaCl₂ is 1: 1

Thus;

Moles of CaCl₂ produced is 1.0 moles

Step 3: Mass of CaCl₂ produced

Moles of CaCl₂ = 1.0 mole

Molar mass CaCl₂ = 110.98 g/mol

But; mass = number of moles × Molar mass

Therefore;

Mass of CaCl₂ = 1.0 mole × 110.98 g/mol

= 110.98 g CaCl₂

3 0

2 years ago

An atom in a pure metal that's face-centered cubic has ___ neighbor atoms.

Lana71 [14]

Answer is: an atom in a pure metal that's face-centered cubic has 12 neighbor atoms.

Fce-centered cubic has eight atoms at each corner of the cube and six atoms at each face of the cube.

Metals that possess face-centered cubic structure are copper (Cu), aluminum (Al), silver (Ag) and gold (Au).

There is three types of cubic cell:

1) simple cubic unit cell.

2) body-centered cubic unit cell.

3) face-centered cubic-unit cell.

3 0

3 years ago