I2 + Na2S2O3 → NaI + Na2S4O6

Suppose that a certain fortunate person has a net worth of $77.0 billion ($). If her stock has a good year and gains $3.20 billi

marissa [1.9K]

Answer:

New net worth to three significant figures = $80.2 billion

Dollars are given to charity = $100,250,000

Explanation:

Net worth = $77.0 billion

stock Gains = $3.20 billion

New net worth = $77.0 billion + $3.20 billion = $80.20 billion

New net worth to three significant figures = $80.2 billion

One-eighth of a percent = (1/8 x 1) / 100 = 0.00125

Dollars are given to charity = 0.00125 X $80.2 billion = $100,250,000

Or

$80,200,000,000/100 = $802,000,000

3 0

4 years ago

2

son4ous [18]

Answer: The molar enthalpy change is 73.04 kJ/mol

Explanation:

$HCl+NaOH\rightarrow NaCl+H_2O$

moles of HCl= $molarity\times {\text {vol in L}}=0.415mol/L\times 0.1=0.0415mol$

As NaOH is in excess 0.0415 moles of HCl reacts with 0.0415 moles of NaOH.

volume of water = 100.0 ml + 50.0 ml = 150.0 ml

density of water = 1.0 g/ml

mass of water = $volume \times density=150.0ml\times 1.0g/ml=150.0g$

$q=m\times c\times \Delta T$

q = heat released

m = mass = 150.0 g

c = specific heat = $4.184J/g^0C$

$\Delta T$ = change in temperature = $4.83^0C$

$q=150.0\times 4.184\times 4.83$

$q=3031.3J$

Thus 0.0415 mol of HCl produces heat = 3031.3 J

1 mol of HCL produces heat = $\frac{3031.3}{0.0415}\times 1=73043.3J=73.04kJ$

Thus molar enthalpy change is 73.04 kJ/mol

8 0

3 years ago

Calculate the approximate volume of a 0.6000mol sample of gas at 288.15K and a pressure of 1.10atm.

11111nata11111 [884]

Answer:

The volume of the sample of the gas is found to be 12.90 L.

Explanation:

Given pressure of the gas = P = 1.10 atm

Number of moles of gas = n = 0.6000 mole

Temperature = T = 288.15 K

Assuming the volume of the gas to be V liters

The ideal gas equation is shown below

$\textrm{PV} =\textrm{nRT} \\1.10 \textrm{ atm}\times V \textrm{ L} = 0.6000 \textrm{ mole}\times 0.0821 \textrm{ L.atm.mol}^{-1}.K^{-1}\times 288.5\textrm{K} \\\textrm{V} = 12.90 \textrm{ L}$

Volume occupied by gas = 12.90 L

6 0

4 years ago

(b) Why is nitrogen used for storage of semen<br>in artificial insemination?

aev [14]

Nitrogen is often used for the storage of semen samples for artificial insemination of cattle. Nitrogen is used to maintain a dry inert atmosphere over chemicals during storage, reaction or processing. Used in brewing, soft drinks and wine-making industries to exclude air from the product and de-aerate water.

3 0

3 years ago

A gas mixture is made up of kr (21.7 g), o2 (7.18 g), and co2 (14.8 g). the mixture has a volume of 23.1 l at 59 °c. calculate t

Scilla [17]

Answer:- partial pressure of Kr = 0.306 atm, partial pressure of oxygen = 0.264 atm and partial pressure of carbon dioxide = 0.396 atm

Total pressure is 0.966 atm

Solution:- moles of Kr = 21.7 g x (1mol/83.8g) = 0.259 mol

moles of oxygen = 7.18 g x (1mol/32g) = 0.224 mol

moles of carbon dioxide = 14.8 g x (1mol/44g) = 0.336 mol

Volume of container = 23.1 L and the temperature is 59 + 273 = 332 K

From ideal gas law equation, P = nRT/V

partial pressure of Kr = (0.259 x 0.0821 x 332).23.1 = 0.306 atm

partial pressure of oxygen = (0.224 x 0.0821 x 332)/23.1 = 0.264 atm

partial pressure of carbon dioxide = (0.336 x 0.0821 x 332)/23.1 = 0.396 atm

Total pressure of the gas mixture = 0.306 atm + 0.264 atm + 0.396 atm = 0.966 atm

4 0

3 years ago