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3 years ago

Why are carcinogens difficult for toxicologists to identify

Chemistry

1 answer:

Jet001 [13]3 years ago

4 0

Answer:

Carcinogens are difficult to identify because there may be a long lag time between exposure to the agent and the detectable onset of cancer

Explanation:

quizlet.com/193673418/environmental-chapter-9-flash-cards/

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An object with a mass of 7.1 g raises the level of water in a graduated cylinder from 25.1 mL to 32.4 mL. What is the density of

jeka57 [31]

Answer:

0.9726g/ml

0.9726g/cm³

Explanation:

Density is found by dividing mass by volume.

Density = mass/volume

mass = 7.1g

volume= the new level of water raised - the initial level of water

volume = 32.4 - 25.1

volume = 7.3 ml

Volume is the amount of space occupied by an object.meaning the amount of volume displaced by the object is its volume.

density = 7.1 /7.3

density = 0.9726g/ml

or 0.9726 g/cm³

If you need any clarification or more explanation pls do mention at the comment section.

hope this helps and if it does pls mark as branliest answer thx

5 0

3 years ago

Question 23

Schach [20]

Answer:

Option B. 0.136 g

Explanation:

The balanced equation for the reaction is given below:

2AgNO3(aq) + 2NaOH(aq) —> Ag2O(s) + 2NaNO3(aq) + H2O(l)

Next, we shall determine the masses of AgNO3 and NaOH that reacted and the mass of Ag2O produced from the balanced equation. This is illustrated below:

Molar mass of AgNO3 = 108 + 14 + (16x3) = 170g/mol

Mass of AgNO3 from the balanced equation = 2 x 170 = 340g

Molar mass of NaOH = 23 + 16 + 1 = 40g/mol

Mass of NaOH from the balanced equation = 2 x 40 = 80g

Molar mass of Ag2O = (108x2) + 16 = 232g/mol

Mass of Ag2O from the balanced equation = 1 x 232 = 232g

Summary:

From the balanced equation above,

340g of AgNO3 reacted with 80g of NaOH to produce 232g of Ag2O.

Next, we shall determine the limiting reactant. This can be obtained as follow:

From the balanced equation above,

340g of AgNO3 reacted with 80g of NaOH.

Therefore, 0.2g of AgNO3 will react with = (0.2 x 80)/340 = 0.047g of NaOH.

From the calculations made above, only 0.047g out of 0.2g of NaOH given, reacted completely with 0.2g of AgNO3. Therefore, AgNO3 is the limiting reactant and NaOH is the excess reactant.

Now, we can calculate the mass of Ag2O produced from the reaction of 0.2g of AgNO3 and 0.2g of NaOH.

In this case, we shall use the limiting reactant because it will produce the maximum yield of Ag2O as all of it is used up in the reaction.

The limi reactant is AgNO3 and the mass of Ag2O produced can be obtained as follow:

From the balanced equation above,

340g of AgNO3 reacted to produce 232g of Ag2O.

Therefore, 0.2g of AgNO3 will react to produce = (0.2 x 232)/340 = 0.136g of Ag2O.

Therefore, 0.136g of Ag2O was produced from the reaction.

8 0

3 years ago

What is the empirical formula for a compound that is 29.44\% calcium, 23.55% sulfur, and 47.01% oxygen? This compound is a commo

PSYCHO15rus [73]

Answer:

Empirical formula is CaSO₄.

Explanation:

Given data:

Percentage of calcium =29.44%

Percentage of sulfur = 23.55%

Percentage of oxygen = 47.01%

Empirical formula = ?

Solution:

Number of gram atoms of Ca = 29.44 / 40 = 0.74

Number of gram atoms of S = 23.55 / 32 = 0.74

Number of gram atoms of O = 47.01 / 16 = 3

Atomic ratio:

Ca : S : O

0.74/0.74 : 0.74/0.74 : 3/0.74

1 : 1 : 4

Ca : S : O = 1 : 1 : 4

Empirical formula is CaSO₄.

3 0

3 years ago

(C6H6) can be biodegraded by microorganism. if 30 mg of benzene is present, what amount of oxygen required for biodegradation, n

quester [9]

Answer:

36.92 mg of oxygen required for bio-degradation.

Explanation:

$5C_6H_6+15O_2\rightarrow 12CO_2+15H_2O$

Mass of benzene = 30 mg = 0.03 g (1000 mg = 1 g )

Moles benzene = $\frac{0.03 g}{78 g/mol}=0.0003846 mol$

According to reaction 5 moles of benzene reacts with 15 moles of oxygen gas.

Then 0.0003846 mol of benzene will react with:

$\frac{15}{5}\times 0.0003846 mol=0.0011538 mol$ of oxygen gas

Mass of 0.0011538 moles of oxygen gas:

0.0011538 mol × 32 g/mol = 0.03692 g = 36.92 mg

36.92 mg of oxygen required for bio-degradation.

4 0

3 years ago

How do you convert from grabs to moles of a substance

Lorico [155]

The correct question is as follows:

How do you convert from grams to moles of a substance

1. Divide by the molar mass

2. Subtract the molar mass

3. Add the molar mass

4. Multiple by the molar mass

Answer: In order to convert from grams to moles of a substance divide by the molar mass.

Explanation:

The number of moles of a substance is the mass of substance in grams divided by its molar mass.

The formula to calculate moles is as follows.

$Moles = \frac{mass}{molar mass}$

This means that grams are converted to moles when grams is divided by molar mass.

Thus, we can conclude that in order to convert from grams to moles of a substance divide by the molar mass.

8 0

3 years ago