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jolli1 [7]
3 years ago
7

Pls i need help with this

Chemistry
1 answer:
gregori [183]3 years ago
5 0

Answer:

C

Explanation:

A physical change is one in which no new substance is formed. The moistening of food by saliva is purely a physical change because no new substance is formed in the process.

A chemical change leads to the formation of a new substance. The action of the enzyme converts starch into sugar which means that a new substance is formed. This is a chemical change.

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The temperature inside your freezer is 0 degrees Celsius. You place a balloon with an initial temperature of 30 degrees C and a
blsea [12.9K]

Answer:

V=0.68L

Explanation:

For this question we can use

V1/T1 = V2/T2

where

V1 (initial volume )= 0.75 L

T1 (initial temperature in Kelvin)= 303.15

V2( final volume)= ?

T2 (final temperature in Kelvin)= 273.15

Now we must rearrange the equation to make V2 the subject

V2= (V1/T1) ×T2

V2=(0.75/303.15) ×273.15

V2=0.67577931717

V2= 0.68L

4 0
3 years ago
Part 1. Determine the molar mass of a 0.622-gram sample of gas having a volume of 2.4 L at 287 K and 0.850 atm. Show your work.
zaharov [31]

If a sample of gas is a 0.622-gram, volume of 2.4 L at 287 K and 0.850 atm. Then the molar mass of the gas is 7.18 g/mol

<h3>What is an ideal gas equation?</h3>

The ideal gas law (PV = nRT) relates to the macroscopic properties of ideal gases.

An ideal gas is a gas in which the particles (a) do not attract or repel one another and (b) take up no space (have no volume).

Given :

  • V = 2.4 L = 0.0024
  • P = 86126.25 Pa
  • T =  287 K
  • m = 0.622
  • R = 8.314

The ideal gas equation is given below.

n = PV/RT

n = 86126.25 x 0.0024 / 8.314 x 287

n = 0.622 / molar mass (n = Avogardos number)

Molar mass =  7.18 g

Hence, the molar mass of a 0.622-gram sample of gas having a volume of 2.4 L at 287 K and 0.850 atm is 7.18 g

More about the ideal gas equation link is given below.

brainly.com/question/4147359

#SPJ1

4 0
1 year ago
A sample that weighs 107.75 g is a mixture of 30% helium atoms and 70% krypton atoms. How many particles are present in the samp
r-ruslan [8.4K]
<span>A sample that weighs 107.75 g is a mixture of 30% helium atoms and 70% krypton atoms. How many particles are present in the sample?    </span>3.59
5 0
3 years ago
What mass of O2, in grams, is required to completely react with 0.025 g C3H8?
8090 [49]
2C3H8+ 702--->6CO2+8H20
FROM  Equation  above  2  moles of C3H8    reacted with  7  moles  of oxygen  to  form   6  moles of  c02 plus  8  molesof  H2O  
the  moles  of  c3H8  reacted is = MASS/ R.F.M
THE  R.F.M =48+8=44
Number  of  moles is  hence 0.025/44=5.68x10^-4
 
since  ratio  of  C3H8  to   O2 is  2:7  Therefore moles of   O2  reacted  is  1.989 x10^-3
mass= r.f.m  x  number  of  moles
(1.989x10^-3)   x  32 =0.064g
6 0
3 years ago
Why is it important for scientists to form a consensus on scientific issues?
KATRIN_1 [288]

Answer:

It is important for scientists to form a consensus on scientific issues because scientific consensus tells us things that we have already learned.

5 0
3 years ago
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