All categories

4 years ago

Which observation most likely indicates that a physical change has taken place?(1 point)

Chemistry

2 answers:

swat324 years ago

8 0

Answer:

Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. ... Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.

If this satisfies you please consider giving me brainliest :)

lys-0071 [83]4 years ago

5 0

Answer:

1 , D

2. D

3. D

Explanation:

1.changes to crystal form, textural change, shape, size, color, volume and density.

2. because the chemical components are still the same( h2o) in order to change it back you have to do a physical change

3. because the process is irreversible physically and you will have to do a chemical change to change it back ( if thats even possible which to rn its not )

You might be interested in

2. How many grams of water can be warmed from 25.0°C to 37.0°C by the addition of 8,064 calories?

sertanlavr [38]

Answer:

672 g

Explanation:

We can calculate the mass of water that can be warmed from 25.0°C to 37.0°C by the addition of 8,064 calories using the following expression.

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

where,

c: specific heat of the water

m: mass

ΔT: change in the temperature

$m = \frac{Q}{c \times \Delta T } = \frac{8,064cal}{(1cal/g. \° C) \times (37.0 \° C - 25.0 \° C) } = 672 g$

The mass of water that can be warmed under these conditions is 672 grams.

5 0

3 years ago

How many moles is ( 1 x 10^9 ) molecules O2

Effectus [21]

Answer:

The answer is

$1.66 \times {10}^{ - 15} \: \: moles$

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

$n = \frac{N}{L} \\$

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

$n = \frac{1 \times {10}^{9} }{6.02 \times {10}^{23} } \\$

We have the final answer as

$1.66 \times {10}^{ - 15} \: \: moles$

Hope this helps you

4 0

3 years ago

A solution is prepared at that is initially in benzoic acid , a weak acid with , and in sodium benzoate . Calculate the pH of th

Kisachek [45]

Answer:

$pH=4.1$

Explanation:

Hello,

In this case, for a concentration of 0.42 M of benzoic acid whose Ka is 6.3x10⁻⁵ in 0.33 M sodium benzoate, we use the Henderson-Hasselbach equation to compute the required pH:

$pH=pKa+log(\frac{[base]}{[acid]} )$

Whereas the concentration of the base is 0.33 M and the concentration of the acid is 0.42 M, thereby, we obtain:

$pH=-log(Ka)+log(\frac{[base]}{[acid]} )\\\\pH=-log(6.3x10^{-5})+log(\frac{0.33M}{0.42M} )\\\\pH=4.1$

Regards.

3 0

4 years ago

consider the reaction between acetylene C2H2 and oxygen in a welding torch 2C2H2 + 5O2 = 4CO2 + 2H2O of 5.4 moles of acetylene r

Eddi Din [679]

Answer:

C. 4.8*10² g.

Explanation:

5 0

3 years ago

Joints can only be moveable. True False

oksano4ka [1.4K]

Answer:

TRue

Explanation:

4 0

3 years ago