Chemical Reactions Test Period 4

It is colder than the other two because the reaction is happening at a slower rate

Al 1,2 Al 2
O 7,10,18 O 13,16,18
H 8,12 H 2,8,12
S 1,3 S 3

C 3 C 1,3
H 8 H 8
O 2,10 O 10

The correct reaction is A2 + B2 --> 2AB because it follows the given information that one molecule of A2 and one molecule of B2 react to form 2 molecules of AB. This reaction shows the correct stoichiometry and product formation.

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The given correct answer is "exothermic." In this context, the heaters in Army MRE's release heat when water is added, resulting in hot and delicious food. This suggests that the reaction involved is exothermic, as it releases heat energy into the surroundings.

Chemists need to work with balanced equations because of the law of conservation of mass. This law states that matter cannot be created or destroyed in a chemical reaction, only rearranged. By balancing the equations, chemists ensure that the same number of atoms of each element is present on both sides of the equation, maintaining the mass balance. This allows for accurate calculations and predictions of the amounts of reactants and products involved in a reaction.

A chemical reaction occurs when bonds between atoms are broken and rearranged to form new chemicals. This process involves the conversion of reactants into products, resulting in a change in the chemical composition of the substances involved. Unlike physical changes, which only affect the physical properties of a substance (such as shape, size, or state), chemical reactions involve a transformation at the molecular level. Therefore, the correct answer is chemical reaction.

This is a decomposition because the image shows a larger substance being broken down into smaller substances

The given correct answer is "High". This is because if the bond between A-A or B-B is very strong, it means that it requires a significant amount of energy to break those bonds and initiate the reaction. Therefore, the activation energy for the reaction will be high.

Increasing the temperature of milk does not necessarily make it unsafe to drink. However, if the temperature is increased too much, it can lead to the growth of bacteria and spoilage of the milk. The safety of drinking milk depends on factors such as the duration and extent of temperature increase, storage conditions, and the milk's freshness. As long as the milk flavor does not start to decrease, it is likely safe to consume.

At the 20 second mark of this experiment, a magical reaction occurs. Based on the given options, the correct answer is endothermic. In an endothermic reaction, heat is absorbed from the surroundings, resulting in a decrease in temperature. This suggests that at the 20 second mark, the reaction in the experiment absorbs heat from its surroundings, indicating an endothermic process.

The reaction N2 + H2 => NH3 is a synthesis reaction. In a synthesis reaction, two or more substances combine to form a single, more complex substance. In this case, nitrogen gas (N2) and hydrogen gas (H2) combine to form ammonia (NH3).

At a higher concentration, the reaction rate is faster because there are more reactant molecules present, leading to more frequent collisions and increased chances of successful reactions. As a result, a greater amount of products is formed in a shorter period of time.

The surface area of a substance affects the rate of reaction. When a tablet is crushed, it increases the surface area, allowing more particles to come into contact with the water molecules. This increases the chances of successful collisions and speeds up the dissolution process. Additionally, warm water molecules have more kinetic energy, which enhances the movement of particles and increases the rate of dissolution. Therefore, using a crushed tablet in warm water would provide the largest surface area and the highest temperature, resulting in the fastest dissolution of the alka seltzer tablet and the quickest absorption of the medicine into the body.

The given reaction involves the combustion of C10H22 (a hydrocarbon) with O2 (oxygen) to produce CO2 (carbon dioxide) and H2O (water). Combustion reactions are characterized by the rapid combination of a substance with oxygen, resulting in the release of heat and light. In this case, the hydrocarbon is being oxidized by oxygen to produce carbon dioxide and water, which are the typical products of a combustion reaction. Therefore, the correct answer is combustion.

This reaction is a single replacement reaction because the lithium (Li) replaces the hydrogen (H) in the water (H2O) to form lithium hydroxide (LiOH) and hydrogen gas (H2). In a single replacement reaction, one element replaces another element in a compound.

Colorado because the pressuere would be less

This reaction is a double replacement reaction because the cations (K+ and H+) and the anions (OH- and Br-) from the reactants switch partners to form new compounds (KBr and H2O) in the product.

This reaction is a double replacement reaction because the cations and anions in the reactants switch places to form new compounds. In this case, the aluminum hydroxide (Al(OH)3) reacts with hydrobromic acid (HBr) to form aluminum bromide (AlBr3) and water (H2O).

The answer is surface area because a substance broken down into smaller chips would have a greater surface area making the reaction happen faster

The given answer suggests that the formation of product AB is not likely to occur. This is because while the bond strength of the reactants is strong, the strength of the product bond is weak. This implies that the reactants are more stable in their current form and are unlikely to form the product AB.

In a chemical change, bonds between atoms are broken and atoms are rearranged to form new substances. This is different from a physical change where no new substances are formed and atoms are not lost. In a physical change, bonds may be broken, but they are not rearranged to form new substances like in a chemical reaction. Therefore, the correct answer is that in a chemical change, bonds are broken and atoms are rearranged.

adding a catalyst would aid in breaking the bonds without changing the reaction

you must DECREASE the pressure in order to increase the reaction rate. This is because decreasing the pressure will allow for the particles to move faster and contact each other more often