Hess’s Law can be used to determine the heat of reaction in the lab. True False

The age of fossils can sometimes be determined by radiometric dating, which is based on the constant rate of decay of radioactiv

True [87]

The age of the fossil given the present amount of Carbon-14 is given in the equation,
A(t) = A(o)(0.5)^t/h
where A(t) is the current amount, A(o) is the initial amount, t is time and h is the half-life. Substituting the known values to the equation,
A(t) / A(o) = 0.125 = (0.5)^(t/5730)
The value of t from the equation is 17190.
Thus, the age of the fossil is mostly likely to be 17190 years old.

8 0

3 years ago

1.Using the absorbance of the spinach extract and the equation of the trendline, determine the concentration of the extract solu

lys-0071 [83]

Answer:

Explanation:

From the given information:

We are to make use of the spinach absorbance extract which is the corrected absorbance (y) = 0.306

And also the trendline equation:

y = 1609x + 0.0055

where,

x = absorbance of the spinach extract.

∴

0.306 = 1609x + 0.0055

collecting the like terms

0.306 - 0.0055 = 1609x

0.3005 = 1609x

x = 0.3005/1609

x = 1.8676 × 10⁻⁴

x ≅ 0.0002 M

No. of grams for the chlorophyll can be computed as follows:

recall that:

molar mass of chlorophyll = 893.5 g/mol

the volume = 25ml = (25/1000) L = 0.025 L

∴

In spinach solution, the no. of grams for the chlorophyll:

= (0.0002) mol/L × (893.5 g/mol) × (0.025) L

= 0.0044675 g

≅ 0.0045 g

In the spinach, the concentration of chlorophyll = no of grams of chlorophyll/ mass of the spinach

= 4.5 mg/0.1876 g

= 23.987 mg/g

≅ 24 mg/g

4 0

3 years ago

Balance them i dont get how

baherus [9]

Add in the numbers in pen

5 0

3 years ago

A certain metal forms a soluble sulfate salt . suppose the left half cell of a galvanic cell apparatus is filled with a solution

svp [43]

Answer:

1. The positive electrode is the one on the left

2. Ecell = 0.0582V

Note: The question is incomplete.

The complete question is given below:

A certain metal M forms a soluble sulfate salt M2SO4. Suppose the left half cell of a galvanic cell apparatus is filled with a 5.00 M solution of M2SO4 and the right half cell with a 500 mM solution of the same substance. Electrodes made of M are dipped into both solutions and a voltmeter is connected between them. The temperature of the apparatus is held constant at 20.0 °C. Which electrode will be positive? What voltage will the voltmeter show? Assume its positive lead is connected to the positive electrode. Be sure your answer has a unit symbol, if necessary, and round it to 2 significant digits.

Explanation:

1. This is a case of a concentration cell. A concentration cell acts to dilute the more concentrated solution and concentrate the more dilute solution, creating a voltage as the cell reaches an equilibrium. This is achieved by transferring the electrons from the cell with the lower concentration to the cell with the higher concentration.

Electrons flow from the right electrode to the left electrode. Therefore, the left electrode is the positive electrode (cathode).

2. See attachment below for solutions

5 0

3 years ago

120.0 liters of a gas are prepared at a pressure of 300.0 mm Hg and a temperature of 100.0 °C. The gas is placed into a tank und

rewona [7]

Answer:

Is 674.8 L

Explanation:

7 0

3 years ago