All categories

3 years ago

What are 3 examples of physical change?

Chemistry

1 answer:

bazaltina [42]3 years ago

3 0

Just breaking stuff so yea that’s it

You might be interested in

If starch, glucose and NaCl are soaked in the dialysis tubing , will there be a difference between the beginning and after 15min

spin [16.1K]

<span>Yes. If you put solutions containing the same concentration table salt, glucose and starch in different bags and place the bags in water (i.e., 0M) solution, then the bag with salt will contain more water after 15 minutes than the bag with glucose, which will contain more than the bag with starch.</span>

6 0

3 years ago

I took 100 micrograms of vitamin d yesterday (13yrs old) is it bad

Amanda [17]

Answer:

take 75 gm or it will be overdose

6 0

2 years ago

Which of the following is an example of symbiosis?

KengaRu [80]

D. One chimp cleaning and grooming the hair of another chimp

5 0

3 years ago

Read 2 more answers

Thallium-207 decays exponentially with a half life of 4.5 minutes. if the initial amount of the isotope was 28 grams, how many g

Agata [3.3K]

An exponential decay law has the general form: A = Ao * e ^ (-kt) =>

A/Ao = e^(-kt)

Half-life time => A/Ao = 1/2, and t = 4.5 min

=> 1/2 = e^(-k*4.5) => ln(2) = 4.5k => k = ln(2) / 4.5 ≈ 0.154

Now replace the value of k, Ao = 28g and t = 7 min to find how many grams of Thalium-207 will remain:

A = Ao e ^ (-kt) = 28 g * e ^( -0.154 * 7) = 9.5 g

Answer 9.5 g.

7 0

3 years ago

Magnesium metal (0.100 mol) and a volume of aqueous hydrochloric acid that contains 0.500 mol of HCl are combined and react to c

jok3333 [9.3K]

Answer:

2.24 L of hydrogen gas, measured at STP, are produced.

Explanation:

Given, Moles of magnesium metal, $Mg$ = 0.100 mol

Moles of hydrochloric acid, $HCl$ = 0.500 mol

According to the reaction shown below:-

$Mg_{(s)} + 2HCl_{(aq)}\rightarrow MgCl_2_{(aq)} + H_2_{(g)}$

1 mole of Mg reacts with 2 moles of $HCl$

0.100 mol of Mg reacts with 2*0.100 mol of $HCl$

Moles of $HCl$ must react = 0.200 mol

Available moles of $HCl$ = 0.500 moles

Limiting reagent is the one which is present in small amount. Thus, $Mg$ is limiting reagent.

The formation of the product is governed by the limiting reagent. So,

1 mole of $Mg$ on reaction forms 1 mole of $H_2$

0.100 mole of $Mg$ on reaction forms 0.100 mole of $H_2$

Mole of $H_2$ = 0.100 mol

At STP,

Pressure = 1 atm

Temperature = 273.15 K

Volume = ?

Using ideal gas equation as:

$PV=nRT$

where,

P is the pressure

V is the volume

n is the number of moles

T is the temperature

R is Gas constant having value = 0.0821 L.atm/K.mol

Applying the equation as:

1 atm × V L = 0.100 × 0.0821 L.atm/K.mol × 273.15 K

2.24 L of hydrogen gas, measured at STP, are produced.

4 0

3 years ago