"solid potassium iodide decomposes into iodine gas and solid potassium. Write a a balanced chemical equation for this reaction"

The first compound to precipitate will be AgI. Explanation: To form a precipitate from a salt solution, the ionic product must surpass the solubility product. Given that AgI has a significantly low Ksp, it will precipitate before PbI2 does. The concentration of AgI solution also affects precipitation speed; the highest concentration of AgI in the choices provided is...

Answer:

thickness is 0.29 cm

Explanation:

To create a fake iron ball out of gold, we must ensure that its mass matches that of the iron ball. Therefore, we first find the volume of the iron ball using the provided diameter, applying the formula of 4/3 pi r^3.

Given the diameter d = 6 cm; thus, the radius r = 3 cm (d/2).

We calculate the volume of the iron ball: 4/3 * 3.14 * 3^3 = 113.04 cm^3.

The corresponding mass of the iron ball is the volume multiplied by its density: 113.04 * 5.15 g/cm^3 = 582.156 g.

This value represents the mass for the gold ball; now we determine the volume of the gold ball using its density.

Volume of gold ball = mass of gold ball/density of gold = 582.156 g/19.3 g/cm^3 = 30.1635 cm^3.

So this volume must correspond to a hollow sphere with an outer radius R = 3 cm and an unknown inner radius r.

Volume of the hollow ball can be represented as: 4/3 pi [R^3 - r^3].

Thus, 30.1635 cm^3 = 4/3 pi [3^3 - r^3].

30.1635 * 3/(4 * 3.14) = 27 - r^3.

Simplifying gives 7.2046 = 27 - r^3, resulting in r^3 = 19.7954.

Therefore, r = 2.7051 cm.

This indicates the thickness is the outer radius minus the inner radius: 3 - 2.7051 = 0.2949 cm.

Rounding to two significant figures yields

the thickness = 0.29 cm.

Answer:

0.5 g/mL----- will float

1.0 g/mL---- will float

2.0 g/mL----- will sink

Explanation:

Objects with a density less than or equal to that of water will float due to having a lower mass, while objects with a density exceeding that of water will sink because their mass is greater than that of water. Thus, objects with a density of 0.5 g/mL and 1.0 g/mL will float since they are less dense than water (1 g/mL), whereas an object with a density of 2.0 g/mL will sink.

Answer:

Amount of salt in 1 L seawater = 34 g

Explanation:

Based on Archimedes' principle, the mass of fresh water and the mass of the cup are equal to the mass of the same volume of seawater.

The mass of freshwater can be calculated using density times volume.

1 cm³ is equivalent to 1 mL.

The mass of freshwater is 0.999 g/cm³ multiplied by 735 cm³, which results in 734.265 g.

The total mass of the freshwater and cup combined is 734.265 g plus 25 g, equating to 759.265 g.

This means the mass for an equal volume of seawater is 759.265 g.

The volume of the seawater displaced is 735 mL, which is 0.735 L (assuming the cup's volume can be disregarded).

We know that 1 liter equals 1000 cm³ or 1000 mL.

The density of seawater can be determined as mass divided by volume.

The density of seawater becomes 759.265 g divided by 0.735 L, yielding 1033.01 g/L.

Conversely, the density of freshwater in g/L is calculated as 0.999 g/(1/1000) L, equating to 999 g/L.

The mass of salt dissolved in 1 liter of seawater is calculated as 1033.01 g - 999 g, which equals 34.01 g.

Thus, the amount of salt in 1 L of seawater is 34 g.

The energy needed to vaporize 1.5 kg of aluminum amounts to 16.345 GJ. The heat of vaporization for aluminum is given as ΔHvap = 294000 kJ/mol. The mass of aluminum in this case equals 1.5 kg which converts to 1500 g. We can calculate the number of moles of aluminum using the formula: Mass of aluminum/(Molar Mass of aluminum). The Molar Mass of aluminum stands at 26.98 g/mol. Using this information, Number of moles calculates to 1500/26.98, which equals 55.6 moles. The total energy required can be expressed as the product of the heat of vaporization and the number of moles of aluminum, so the energy required calculates to 294000 × 55.6, resulting in 16345441.0675 kJ or approximately 16.345 GJ.