A ball is rolled at a velocity of 3 m/s and rolls for 5 seconds. How far does the ball roll? *

How many Joules are released to cool 250.0 grams of liquid water from 100°C to 0°C? The specific heat of water is 4.180 J/g.C.

nlexa [21]

$\bold{\huge{\orange{\underline{ Solution}}}}$

$\bold{\underline{ Given :- }}$

We have 250g of liquid water and it needs to be cool at temperature from 100° C to 0° C
Specific heat of water is 4.180J/g°C

$\bold{\underline{ To \: Find :- }}$

We have to find the total number of joules released.

$\bold{\underline{ Let's \:Begin:- }}$

We know that,

Amount of heat energy = mass * specific heat * change in temperature

That is, 

$\sf{\red{ Q = mcΔT }}$

Subsitute the required values in the above formula :-

$\sf{ Q = 250 × 4.180 ×(0 - 100 )}$

$\sf{ Q = 250 × 4.180 × - 100 }$

$\sf{ Q = 250 × - 418}$

$\sf{\pink{ Q = - 104,500 J }}$

Hence, 104,500 J of heat is released to cool 250 grams of liquid water from 100° C to 0° C.

$\bold{\underline{ Now :- }}$

We have to tell whether the above process is endothermic or exothermic :-

Here, In the above process ΔT is negative and as a result of it Q is also negative that means above process is Exothermic

Exothermic process :- It is the process in which heat is evolved .
Endothermic process :- It is the process in which heat is absorbed .

4 0

2 years ago

Two scientists wrote a paper detailing their research and conclusions and submitted it to a scientific journal. Several months l

Semmy [17]

Two scientists wrote a paper detailing their research and conclusions and submitted it to a scientific journal. Several months later, they received the paper back from the publisher with many comments attached from several fellow scientists. It is either that they revise their study or replicate the study. Most scientists would revisit their work and the findings they had from their research. Most probable if they were successful and the comments of the publisher and the co-scientists were positive they could replicate the study to validate its accountability.

6 0

3 years ago

When 2-phenylacetaldehyde is added dropwise to benzaldehyde in the presence of sodium hydroxide they undergo a crossed aldol rea

egoroff_w [7]

Carbonyl Compounds containing alpha proton readily donates alpha acidic proton when treated with strong Base. In given statement 2-phenylacetaldehyde is converted into Enolate and Enolates acts as a nucleophile and attacks carbonyl group of Benzaldehyde. The mechanism of given reaction is as follow, the movement of electrons is shown by RED arrows,

7 0

3 years ago

NEED ASAP WILL MARK BRAINLIEST ON TIMER

vladimir1956 [14]

Answer:

The answer is 2.660 mol/l

Explanation:

Given: n= 0.0665, v= 25.00ml

Required: C

C (molarity)= n (of solute)/ v (of solvent) [ standard unit: mol/l]

First convert volume of solvent in its standard unit, i.e. litres(L)

v= 25.00ml/1000= 0.02500L

C = 0.0665 mol / 0.02500 L= 2.660 mL (In proper significant digits i.e. 4 sigdigs)

Therefore, The molarity of the sulfuric acid is 2.660 mol/L :)

3 0

3 years ago

True or false: chemical reactions happen and compounds form because they're trying to get 6 electrons in their outer orbitals

wel

Answer:

False

Explanation:

The octet rule forms the basis for chemical reactions. The octet rule states that; an atom is only stable when it has eight electrons around its outermost shell.

This implies that the driving force behind chemical reaction is the attainment of an octet structure(eight electrons in the outermost shell of each of the bonding atoms).

An atom that has only six electrons in its outermost shell is not yet stable according to the demand of the octet rule. Hence, the statement "chemical reactions happen and compounds form because they're trying to get 6 electrons in their outer orbitals" is false.

7 0

2 years ago