What law states that matter can never be created or destroyed?

. Calculate the molality of each of the following solutions: (a) 0.710 kg of sodium carbonate (washing soda), Na2CO3, in 10.0 kg

Step2247 [10]

Answer:

a)0.67 molal

b) 5.67 molal

c) 2.82 molal

d) 0.0268 molal

Explanation:

Step 1: Data given

Molality = moles solute / mass solvent

(a) 0.710 kg of sodium carbonate (washing soda), Na2CO3, in 10.0 kg of water—a saturated solution at 0°C

Calculate moles of Na2CO3 = 710 grams / 105.99 g/mol = 6.70 moles

Molality = 6.70 moles / 10 kg = 0.67 molal

(b) 125 g of NH4NO3 in 275 g of water—a mixture used to make an instant ice pack

Calculate moles of NH4NO3 = 125 grams / 80.04 g/mol = 1.56 moles

molality = 1.56 moles / 0.275 kg = 5.67 molal

(c) 25 g of Cl2 in 125 g of dichloromethane, CH2Cl2

Calculate moles Cl2 = 25 grams / 70.9 g/mol= 0.353 moles

Molality = 0.353 moles / 0.125 kg = 2.82 molal

0.372 g of histamine, C5H9N, in 125 g of chloroform, CHCl3

Calculate moles histamine = 0.372 grams / 111.15 g/moles = 0.00335 moles

Calculate molality = 0.00335 moles / 0.125 kg = 0.0268 molal

NOTE: histamine is C5H9N3 not C5H9N

4 0

3 years ago

Acid indigestion is sometimes neutralized with an antacid such as magnesium hydroxide (Mg(OH)2). What products will be released

Lunna [17]

Answer: d) $MgCl_2$ and $H_2O$ 

Explanation:

A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.

A neutralization reaction is a double displacement reaction in which an acid reacts with base to produce salt and water. The $H^+$ ions from water reacts with $OH^-$ ions from base to give water.

$2HCl+Mg(OH)_2\rightarrow MgCl_2+2H_2O$

Thus products that will be released when the antacid is mixed with the hydrochloric acid in the stomach are $MgCl_2$ and $H_2O$ 

3 0

3 years ago

What makes an element inert?

ozzi

"The inert gases are obtained by fractional distillation of air, with the exception of helium which is separated from a few natural gas sources rich in this element, through cryogenic distillation or membrane separation. For specialized applications, purified inert gas shall be produced by specialized generators on-site. They are often used by chemical tankers and product carriers (smaller not a big as well as the tendency of inert gases vesselshtop specialized generators are also available for laboratories."

3 0

3 years ago

Gas Law- please help!!!

jekas [21]

The pressure of the carbon dioxide will be 0.09079 atm.

<h3>What is partial pressure?</h3>

The pressure exerted by the individual gas is known as partial pressure.

The partial pressure is given as

$\rm P_{Total} = P_1 + P_2 + ...$