All categories

2 years ago

true or false, Discovering which of two materials can scratch the other is a way to compare the hardness of the materials

Chemistry

2 answers:

Shkiper50 [21]2 years ago

7 0

True, the hardness of all materials in relative <span />

Anton [14]2 years ago

7 0

This answer is true :)

You might be interested in

What is the change in internal energy (ΔΕ) of a system when 5 kJ of work is done on the system while it releases 13 kJ of energy

meriva

The change in internal energy (ΔΕ) of a system : -8 kJ

<h3>Further explanation </h3>

The laws of thermodynamics 1 state that: energy can be changed but cannot be destroyed or created

The equation is:

$\tt \Delta U=Q+W$

Energy owned by the system is expressed as internal energy (U)

This internal energy can change if it absorbs heat Q (U> 0), or releases heat (U <0). Or the internal energy can change if the system does work or accepts work (W)

The sign rules for heat and work are set as follows:

• The system receives heat, Q +

• The system releases heat, Q -

• The system does work, W -

• the system accepts work, W +

5 kJ of work is done on the system : W = +5 kJ

releases 13 kJ of energy to the surroundings : Q = -13 kJ

$\tt \Delta E=-13+5=-8~kJ$

6 0

2 years ago

What is the minimum of acetic anhydride (102.1 g/mol) required to react completely with the 2.94 grams of salicylic acid? What v

Lady bird [3.3K]

Answer:

a) the minimun of acetic anhydride required for the reaction is 2.175 g (CH3CO)2O

b) V acetic anhydride = 2.010 mL

Explanation:

balanced reaction:

C6H4OHCOOH + (CH3CO)2O ↔ C9H8O4 + C2H4O2

⇒ mol salicylic acid = 2.94 g C6H4OHCOOH * ( mol C6H4OHCOOH / 138.121 g ) = 0.0213 mol C6H4OHCOOH

⇒ mol acetic anhydride = 0.0213 mol C6H4OHCOOH * ( mol (CH3CO)2O / mol C6H4OHCOOH ) = 0.0213 mol (CHECO)2O

⇒ g acetic anhydride = 0.0213 mol * ( 102.1 g/mol ) = 2.175 g CH3CO)2O

b) V = 2.175 g (CH3CO)2 * ( mL / 1.082 g ) = 2.010 mL (CH3CO)2O

4 0

2 years ago

Scientists observe that iron compounds are able to bind to nutrients in waterways experiencing eutrophication. Which change will

Anettt [7]

(1) Fewer microorganisms will grow on the surface of the lake if iron compounds are added to a lake with an overabundance of nutrients. Hence, option 1 is correct.

(2) Fracking means using water and chemicals at high pressure to open up fissures to access oil and gas resources. Hence, option 2 is correct.

<h3>What are microorganisms?</h3>

An organism that can be seen only through a microscope.

Iron is a natural capping agent which can enhance sediment P binding capacity, thus reducing P availability and shifting a lake from an algal to a macrophyte dominated state. Iron could, however, also impose toxic effects on the biota.

Fracking is the injection of a fluid at high pressure into an underground rock formation to open fissures and allow trapped gas or crude oil to flow through a pipe to a wellhead at the surface.

This technique is used in natural gas and petroleum production.

1) Fewer microorganisms will grow on the surface of the lake if iron compounds are added to a lake with an overabundance of nutrients. Hence, option 1 is correct.

(2) Fracking means using water and chemicals at high pressure to open up fissures to access oil and gas resources. Hence, option 2 is correct

Learn more about the microorganisms here:

brainly.com/question/6699104

#SPJ1

6 0

1 year ago

Answer to the ? In letter b

andreev551 [17]

The answer to letter b is

7 0

1 year ago

Why do different solvents affect adsorbate-surface interactions?

Effectus [21]

Answer:

so that the can fiuger out what it is for the answer

Explanation:

3 0

2 years ago