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The mass of magnesium ribbon increases when heated in air because it combines with oxygen to form magnesium oxide, a white powder: The chemical equation for this reaction is: 2Mg + O2 → 2MgO

1 mole of NaOH per dm3 has a mass of 40g mass of NaOH in 0.125 mole = 0.125 x 40 = 5g mass in 5.00 dm3 of the solution = 5 x 5 = 25.0g

The pH of a solution of sodium carbonate is greater than 7 because it's a basic salt. When Na2CO3 is dissolved in water, it undergoes hydrolysis, which produces OH- ions, making the solution pH greater than 7.

If more heat is applied to an exothermic reaction in equilibrium, it means temperature is increased, this will however, cause the equilibrium shift to the left. This means the product will decompose to produce more of the reactants on the LHS. i.e XY\(_3\) will decompose.

When marble chips (calcium carbonate) react with hydrochloric acid, they produce carbon dioxide gas, water, and calcium chloride. The chemical reaction is represented by the equation CaCO3 + 2HCl → CaCl2 + H2O + CO2. The rate of the reaction is proportional to the number of collisions between reactant molecules. Increasing the concentration of hydrochloric acid increases the number of acid particles in the same volume of liquid, which increases the frequency of collisions. If equal amounts of marble chips react separately with different concentrations of hydrochloric acid, the amount of carbon dioxide gas produced remained the same in each case

Crystallization is the process by which solids form when atoms or molecules are organized into a crystal structure. The resulting crystal's attributes depend on factors like temperature, air pressure, cooling rate, and time of fluid evaporation. copper (II) sulphate pentahydrate (CuSO4⋅5H2O) can be obtained from an aqueous solution of copper (II) tetraoxosulphate (VI) by crystallization.

AgNO3 is also known as lunar caustic because it: Creates a burning sensation and Leaves a black stain similar to the moon. Silver nitrate (AgNO3) will leave a metal residue when heated strongly.

The blue color of the copper sulfate solution fades and eventually turns a pale green or greenish blue color. This is because the iron displaces the copper from the copper sulfate solution, forming ferrous sulfate (FeSO4). A visible change is observed when a strip of iron is placed in an aqueous solution of copper sulfate (CuSO4)

First, write a balanced chemical equation for the neutralization reaction. H\(_2\)SO\(_4\) + 2 NaOH → Na\(_2\)SO\(_4\) + 2H\(_2\)O From the balanced equation, N\(_A\) = 1, N\(_B\) = 2 V\(_A\) = 20 cm\(^3\) ; C\(_A\) = 0.09 moldm\(^{-3}\) ; V\(_B\) = 30 cm\(^3\) ; C\(_B\) = ? Using the formula, \(\frac{C_A V_A}{C_B V_B}\) = \(\frac{N_A}{N_B}\) C\(_B\) = \(\frac{C_A V_A N_B}{V_B N_A}\) = \(\frac{0.09 X 20 X 2}{30 X 1}\) = 0.12 moldm\(^{-3}\)

No expanded working has been attached for this question yet. The verified answer is Option C.

In terms of loss or gain of electron(s), the statement that best describes oxidation is the loss of electrons. Always use the acronym: OIL / RIG. O- Oxidation I - Is L - Loss of electrons R - Reduction I - Is G - Gain of electron

Animal charcoal or bone black is the carbonaceous residue obtained by the dry distillation of bones. It contains only about 10% carbon, the remaining being calcium and magnesium phosphates (80%) and other inorganic material originally present in the bones.

-There are 4 unpaired electrons in Fe -However; 5 unpaired electrons are present in Fe3+

The use of sulfur to vulcanize rubber is made to enhance its properties, making it more durable, elastic, and heat-resistant.

To find the number of moles, we use the formula n = \(\frac{mass}{Molar Mass}\) N.B: [ He = 4, C = 12, K =39, Zn = 65, Ag = 108] A. 8 g of Helium, n = \(\frac{8}{4}\) = 2 moles B. 48 g of Carbon, n = \(\frac{48}{12}\) = 4 moles C. 78 g of Potassium, n = \(\frac{78}{39}\) = 2 moles D. 130g of Zinc, n = \(\frac{130}{65}\) = 2 moles E. 216g of Sliver, n = \(\frac{216}{108}\) = 2moles Comparing the results, the element with the greatest number of moles is B. 48 g of Carbon, containing 4 moles.