A scientist observed that the loss of plants near a stream resulted in more soil being washed downstream. How will the excess so

Calculation yields 209.53. The molar concentration is calculated by moles divided by volume. Given the volume of 750 mL, which translates to 0.75 L, the moles of CuBr₂ can be determined as molar concentration multiplied by volume, resulting in 1.25 × 0.75 = 0.9375. Mole count is derived from the mass of CuBr₂ divided by its molecular mass. The molecular mass of CuBr₂ is computed as 63.5 + 80 × 2 = 223.5, where the mass of Cu is 63.5 and that of Br is 80. Consequently, the mass needed amounts to 223.5 × 0.9375 = 209.53 g.

Explanation:

The scale under her feet exerts an equal force but opposite in direction.

This principle aligns with Newton's third law of motion, which says that "for every action, there is an equal and opposite reaction."

As the girl’s weight presses down on the scale with a force of 42N, the scale responds with an equal upward force in the opposite direction.

The resulting net force is zero, which explains why her weight does not break the scale.

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Force

Answer:

7.3

Explanation:

Using the Henderson Hasselbalch equation, one can determine the pH or pOH of a solution via its pKa. Remember, , and pKa = -logKa, where Ka denotes the acid's equilibrium constant.

The Henderson Hasselbalch formula:

In this context, acid X possesses two ionic forms: the carboxyl group and an alternative form. Initially, we have 0.1 mol/L of acid in 100 mL, which gives:

n1 = (0.1 mol/L)×(0.1 L) = 0.01 mol

Upon dissociation, it yields 0.005 mol of the carboxyl form and 0.005 mol of the other form with stoichiometry assumed constant.

Introducing NaOH at a concentration of 0.1 mol/L and 75 mL, the moles of become:

n2 = (0.1 mol/L)×(0.075 L) = 0.0075 mol

Thus, 0.0075 mol of reacts with 0.005 mol of the carboxyl form, leading to 0.0025 mol of , which in turn reacts with 0.005 mol of the alternating group, leaving 0.0025 mol of the latter.

The new solution’s volume is 175 mL, but the concentrations of both forms remain unchanged in volume, so we can utilize the moles in the equation.

<pNote, the moles of the acid form remain 0.01 mol as it doesn’t undergo reaction!

Thus, we arrive at:

6.72 = pKa - log 4

pKa - log 4 = 6.72

pKa = 6.72 + log 4

pKa = 6.72 + 0.6

pKa = 7.3

Answer: The apparent density of ethylene glycol 3350 is calculated as 3350 = 17g/15.6mL= 1.09g/mL

The specific gravity of the mixture is 1.01

Explanation:

Specific gravity refers to the density of a substance compared to that of a reference substance, typically water.

Specific gravity = density of substance/density of water

The density of a substance measures the mass of that substance relative to its volume.

Density = Mass/Volume

The density of water is known to be 1.00 g/mL,  

Apparent density of ethylene glycol 3350 is assessed as mass/volume

the volume of ethylene glycol = total volume of mixture - volume occupied by water

volume of ethylene glycol = 195.6 - 180 = 15.6 mL

Apparent density of ethylene glycol 3350 = 17g/15.6mL= 1.09g/mL

mass of water is computed as  density of water multiplied by volume of water

mass of water = 1.00g/mL * 180mL = 180 g

Total mass of solution = mass of substance plus mass of water = (17 + 180)g = 197g

Density of the mixture = total mass of the mixture divided by its volume

Density of mixture = 197 g / 195.6 mL = 1.01 g/mL

To find the specific gravity of the mixture, use the formula:

specific gravity of mixture = density of mixture divided by density of water

specific gravity of mixture = 1.01g/mL / 1.00g/mL

specific gravity of mixture = 1.01