October 30, 2017

CH3CH2COOH(aq) + H2O(l) --->  CH3CH2COO−(aq) + H3O+(aq) 

The key to idenitifying Bronsted-Lowry acid-base pair and realizing that acid and base must differ in only one Hydrogen. According to the theory, Bronsted-Lowry acid is a proton (H+) donor, and Bronsted-Lowry base is a proton (H+) acceptor. When looking at the equation we must first look at reactants and then at products. In the equation given above, we see th...

October 27, 2017

When a chemical reaction is at equilibrium,
the concentration of each reactant and the  concentration of each product must be

(1) constant

(2) variable

(3) equal

 (4) zero

Answer and Explanation:

Most chemical reactions do not go to completion, but rather reach equilibrium. This is a state in which the rate of the forward reaction is equal to the rate of the reverse reaction. As reactants are making products, products are m...

October 24, 2017

n Long Island, several businesses use geothermal technology. This involves taking heat from within Earth and using it to heat buildings. One benefit of this technology is that it

(1) contributes to global warming
(2) reduces the ozone shield
(3) reduces dependence on fossil fuels

(4) decreases resources for many species 

Answer and Explanation:

The question asks for one benefit of the use of geothermal technology. Let's fi...

October 21, 2017

Which molecules are needed to cut and copy segments of DNA?

(1) reproductive hormones

(2) carbohydrates
(3) antibodies
(4) biological catalysts 

Answer and Explanation:

All of the answer choices are molecules in our body. Let's look at the definition of each choice one at a time. Reproductive hormones such as testosterone and estrogen function to regulate reproductive functions such as menstrual cycle, sperm production etc...

October 18, 2017

What is the number of electrons shared in the multiple carbon-carbon bond in one molecule of 1-pentyne?

(1) 6

(2) 2

(3) 3

(4) 8 

Answer and Explanation: 

Pentyne is an organic compound. We know from looking at the ending "yne" that this molecules belongs to the class of alkynes if we look at the Reference table. Alkynes are molecules that have a triple bond. Since the question asks us for the number of electrons shared in m...

October 15, 2017

A sample of water is boiling as heat is added at a constant rate. Which statement describes the potential energy and the average kinetic energy of the water molecules in this sample?

(1) The potential energy decreases and the average kinetic energy remains the same.

(2) The potential energy decreases and the average kinetic energy increases.

(3) The potential energy increases and the average kinetic energy remains the same...

October 12, 2017

Which type of reaction involves the transfer of electrons?

(1) alpha decay
(2) double replacement

(3) neutralization
(4) oxidation-reduction 

Answer and Explanation:

Alpha decay is a type of nuclear reaction where the nucleus of parent atom breaks down and releases alpha particle( Helium atom) as well as a new atom. 

In a double replacement reaction, two ionic compounds come together  and switch their partners. Thus, t...

October 9, 2017

The new study, published online July 18 in the Journal of Geophysical Research: Planets, provides a new clue to whether Venus could have ever supported life. According to the new simulations, Venus had just the right amount of cloud cover, carbon dioxide and water to start with, and could have formed an ocean. 

This finding could help researchers find other habitable planets outside of solar system. 

In the...

October 6, 2017

Which formula represents an alkane?

(1) C2H2

(2) C2H4

(3) C3H4

(4) C3H8 

Answer and Explanation: The general formula for an alkane is CnH2n+2. Therefore all we need to do is plus the carbon subscript and find out how many hydrogens are needed to make the formula an alkane. Let's start with choice 1: C2H2, If we plug in 2 for n, we see H must be 2*2+2=6. 

2: C2H4, the number of Hydrogens is still not 6 and is therefore not...

October 3, 2017

A molecule must be nonpolar if the molecule

(1) is linear
(2) is neutral
(3) has ionic and covalent bonding
(4) has a symmetrical charge distribution 

Answer and Explanation:

 A molecule is considered to be non polar when the charge is symmetrically distributed in it or when there is an equal sharing of electrons between the two atoms of a diatomic molecule . Examples of non polar molecules are : O2, CH4, CCl4. In these mo...

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