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3 years ago

551 cal of heat is added to 5.00 g ice at –20.0 °c. what is the final temperature of the water?

1 answer:

5 0

This item can be answered using the equation,

h = mcp(dT) + mHv

where h is the heat, m is the mass of the substance, cp is the specific heat, and dT is the temperature difference, Hv is the latent heat of fusion. Substituting the known values from the given above,

551 cal = (5 g)(1 cal/g°C)(T - -20) + (5 g)(80 cal/g)

The value of T from the equation is 10.2.

Answer: 10.2°C

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Identify which result of a physical rather than a chemical change

Pani-rosa [81]

Explanation:

A physical change is change that alters the physical properties of matter especially its form and state.

In many cases, the change is easily reversible.

Examples are change of state such as boiling, melting, freezing, condensation, sublimation e.t.c

A chemical change is one in which a new kind of matter is formed. It is always accompanied by energy changes.

Examples are combustion, rusting , precipitation, milk souring.

Chemical changes are irreversible
Physical changes do not lead to the formation of new kinds of matter.
Most physical changes requires little energy.

You can use this knowledge to solve your problem

learn more:

Chemical change brainly.com/question/9388643

#learnwithBrainly

8 0

3 years ago

The atomic number of carbon is 6. carbon-14 is heavier than carbon-12 because the atomic nucleus of carbon-14 contains _____ neu

RSB [31]

14-6=8
8 neutrons is the answer

6 0

3 years ago

3. Hydrogen reacts with nitrogen to produce ammonia according to the equation:

lys-0071 [83]

Mass of ammonia produced : 121.38 g

<h3>Further explanation</h3>

Given

Reaction

3H₂(g) + N₂(g) ⇒ 2NH₃(g)

100g of N₂

Required

Ammonia produced

Solution

mol of N₂ :

$\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{100}{28}\\\\mol=3.57$

From the equation, mol ratio of N₂ and NH₃ = 1 : 2, so mol NH₃ :

$\tt \dfrac{2}{1}\times 3.57=7.14~moles$

mass of NH₃(MW=17 g/mol) :

$\tt mass=mol\times MW\\\\mass=7.14\times 17\\\\mass=121.38~g$

8 0

2 years ago

How long will it take for a 750 mg sample of radium with a half life of 15 days to decay to exactly 68mg?

weqwewe [10]

Answer:

52 da

Step-by-step explanation:

Whenever a question asks you, "How long to reach a certain concentration?" or something similar, you must use the appropriate integrated rate law expression.

The i<em>ntegrated rate law for a first-order reaction </em>is

ln([A₀]/[A] ) = kt

Data:

[A]₀ = 750 mg

[A] = 68 mg

t_ ½ = 15 da

Step 1. Calculate the value of the rate constant.

t_½ = ln2/k Multiply each side by k

kt_½ = ln2 Divide each side by t_½

k = ln2/t_½

= ln2/15

= 0.0462 da⁻¹

Step 2. Calculate the time

ln(750/68) = 0.0462t

ln11.0 = 0.0462t

2.40 = 0.0462t Divide each side by 0.0462

t = 52 da

8 0

3 years ago

Which statement about scientific notation is true?

vladimir2022 [97]

Explanation:

the proper format for scientific notation the following conditions must be true

8 0

2 years ago