Phase changes are physical changes (Andrew Rader Studios. 1997-2015) Phase changes are not chemical changes. (Andrew Rader Studios. 1997-2015) The following equations do not involve chemical changes as no new products are being formed, the substances are changing state which is a physical change: • Melting: H2O(s) > H2O(l) • Sublimation: H2O(s) > H2O(g) • Freezing: H2O(l) > H2O(s) Melting an ice cube is a reversible reaction as the chemical composition of H2O is not changed. Only the state is changed from solid to liquid by applying heat, which can be changed back by lowering the temperature enough. There are however some physical changes that cannot be reversed, for example, cracking an egg and grinding a wooden spoon. They both undergo physical …show more content…
2000-2016) In this reaction, there is a physical change as there is a change in the texture and colour of Fe. This reaction involves a chemical change as well; a new substance is formed. 2. Aluminum metal dissolving in an aqueous solution of sulfuric acid to form hydrogen gas bubbles and a solution of aluminum sulfate. Aluminum (s) + Sulfuric acid (aq) > Hydrogen (g) + Aluminum sulfate (aq) 2 Al (s) + 3 H2SO4 (aq) > 3 H2 (g) + Al2(SO4)3 (aq) This reaction undergoes physical and chemical changes, there is a chemical change as there are new products formed and a physical change as there are changes in state. 3. The reaction between silver nitrate and sodium chloride to form sodium nitrate and silver chloride. AgNO3 (aq) + NaCl (aq) → NaNO3 (aq) + AgCl (s) This reaction undergoes physical changes as there is a change in state and also there is a change in colour, after the reaction occurs, a white precipitate is formed. The reaction also undergoes a chemical change as 2 new products are formed. TASK …show more content…
This suggests that the intermolecular forces between molecules within an ionic compound are much stronger than the intermolecular forces between molecules within a covalent compound. The densities of the ionic compounds in table 1 are also higher than the densities in table 2. Due to ionic compounds having stronger intermolecular forces than covalent compounds, the volume of the ionic compound would be less than the volume of the covalent compound. Density=Mass/Volume, so a lower volume would result in a higher density. (Santosh Agray.
After placing the aluminum in said beaker, one should gather a stir stick and stir the solution in order to speed up the reaction. One should stir the solution until there are no visible silver pieces of aluminum left in the beaker of what was the copper (II) chloride solution. When there are no visible silver pieces of aluminum left in the beaker, this means that the reaction has occurred. After the reaction has occurred, one needs to separate the products, which are copper and aluminum chloride, from each other in order to see how much copper was able to be produced. Seeing as the products are a solid in the form of copper and a liquid in the form of aluminum chloride, the process of filtration can be used to separate them.
A mixture of elements is what is known as compounds. Chemical reactions occur when particles react with each other and atoms in molecules get rearranged. Reactions happen either rapidly or slowly. The speed of a reaction is known as the rate of the reaction. This speed of chemical reaction depends on many factors such as temperature, particle size of reactants, and the intensity of reactants.
The initial reaction mixture containing ferrocene, acetic anhydride, and phosphate acid was mixed on a hot stir plate. During this period, reflux was observed, and the mixture appeared dark brown in color. To quench the reaction, the reaction mixture was transferred onto ice. NaOH was slowly added into the mixture, which resulted in acetic acid byproduct from the acetic anhydride reactant/solvent. This resulted in a clumpy and dark mixture.
One of the reactions you observed resulted in this product: NaCl + H2O + CO2 (g)? What well did this reaction occur in? Describe how the observations for this reaction support your answer. B BoldI ItalicsU Underline Bulleted list Numbered list Superscript Subscript70 Words A reaction I observed in number 1.)
In this case, the ice is absorbing the heat from both the environment and the ice cream mixture. An example of an exothermic reaction would be the ice cream forming into a solid because freezing is taking away all of the heat and freezing it. To explain that all the energy is not lost when the ice absorbs the heat, there is the Law of Conservation of Energy. The Law of Conservation of Energy states that energy cannot be created nor destroyed. Hence stating that when the ice absorbs heat from the ice cream mixture all the energy from the transfer of heat energy is not lost, for the ice is melting.
Introduction During this lab, students observed that not all substances dissolve at the same rate. Many factors involved including the independent and dependent variables affect how distinct substances dissolve. Overall, the chemical reaction, “the amount of reactant that changes the product in a given time”, played an important part in this experiment, when proven how a substance can change into another element by either emitting or absorbing energy. (Tro, 2018).
This model was developed in the 1946, and although it has been criticised for been too simplistic (Amory, 2014), Burnes (2004) argues that this theory has been recognised as one of Lewin’s key developments in the change management field. The 3 stage model comprises of Unfreezing, Changing and Refreezing. To demonstrate this theory, Lewin (1946) used the example of reshaping a block of ice. During the unfreezing stage, the block of ice will start to melt which will make it easier to adapt to the change. During the next stage, changing, the melting block can now be reshaped to suit the desired outcome.
Balanced Chemical Equation: Cu(s) + 4HNO3(aq) —> Cu(NO3)2 (aq) + 2NO2 (g) + 2H2O (l) Reaction 2: when sodium hydroxide (NaOH) is added to copper (II) nitrate (Cu(NO3)2), a double displacement reaction will occur. Copper and sodium will displace each other to create copper (II) hydroxide and sodium nitrate. Balanced Chemical Equation: Cu(NO3)2 (aq) + 2NaOH (aq) —> CuOH2 (s) + 2NaNO3 (aq) Reaction 3: When copper (II) hydroxide is heated, a decomposition reaction will occur. The reaction will decompose forming two compounds, Copper (II) oxide, and water. Balanced Chemical Equation: Cu(OH)2 (s) + Heat —> CuO (s)
As such, Jeng (1998) defined it as “There exists a set of initial parameters, and a pair of temperatures, such that given two bodies of water identical in these parameters, and differing only in initial uniform temperatures, the hot one will freeze sooner. ”[1]. However the term “freeze sooner” would still be unclear or ambiguous. It could mean the first to reach nucleation point or the first for all mass of the liquid water to turn into solid ice.
Throughout the experiment, copper was altered a total of 5 times, but after the final chemical reaction, solid, elemental copper returned. Each time the solution changed color, a precipitate formed, or when gas appeared, indicated that a chemical reaction was occurring. For the first reaction, copper was added to nitric acid, forming the aqueous copper (II) nitrate (where the copper went), along with liquid water, and
Ions (particles with a positive charge) are very effective at lowering the freezing point of water because they cause a large disruption in water molecules, weakening the intermolecular forces. The radius of the molecules particles also have an effect
Mixing sugar and sulfuric acid creates a chemical reaction. The properties of sugar include small grainy white particles, while the sulfuric acid is clear and has a low viscosity. When you first introduce sugar to sulfuric acid, the acid dehydrates the sugar. Which causes an exothermic reaction. With this reaction, there is smoke, fumes, and heat that is released.
For example, the results of the aluminum can. Aluminum is the chemical element of atomic number 13, a light silvery-gray metal. When liquid water is heated, it changes to water vapor which pushes all of the molecule air out of the container as it rises. After the liquid water was heated, it was
A liquid has indefinite shape, definite volume, and no compressibility. In addition, gas has indefinite shape, indefinite volume, and compressibility. Furthermore, in order to identify elements, one will have to look at the atomic number, therefore, establishing the number of protons. Last but not least, a chemical change is a change in a substance
Acid can also mobilize the aluminum ions that were previously a harmless part of aluminum hydroxide. These