How many controls or controlled variables can there be in an experiment

What is the purpose of the three R’s of resource management?

Brrunno [24]

<span>The Three R's: Reduce, Reuse and Recycle. The three R's - reduce, reuse and recycle - all help to cut down on the amount of waste we throw away. They conserve natural resources, landfill space and energy.

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3 0

4 years ago

Read 2 more answers

HELP ASAP!! DUE NOW!! WILL MARK AS BRAINLIEST IF ANSWERED WITHIN 5-10 MINUTES

AlladinOne [14]

1. NaCl
2. CaO
3. KOH
4. MgS
5. CuCO3
6. Al2O3
7. Fe2O3
8. Na2CO3
9. AlHO3
10. (NH4)3N
11. Zn3N2
12. MgCO3

All numbers are subscripts.

6 0

3 years ago

Consider the following reaction: CHCl3(g) + Cl2(g) → CCl4(g) + HCl(g) The initial rate of the reaction is measured at several di

Ira Lisetskai [31]

Answer : The correct rate law for the reaction is,

$\text{Rate}=k[CHCl_3][Cl_2]^{1/2}$

Explanation :

Rate law : It is defined as the expression which expresses the rate of the reaction in terms of molar concentration of the reactants with each term raised to the power their stoichiometric coefficient of that reactant in the balanced chemical equation.

For the given chemical equation:

$CHCl_3(g)+Cl_2(g)\rightarrow CCl_2(g)+HCl(g)$

Rate law expression for the reaction:

$\text{Rate}=k[CHCl_3]^a[Cl_2]^b$

where,

a = order with respect to $CHCl_3$

b = order with respect to $Cl_2$

Expression for rate law for first observation:

$0.0035=k(0.010)^a(0.010)^b$ ....(1)

Expression for rate law for second observation:

$0.0069=k(0.020)^a(0.010)^b$ ....(2)

Expression for rate law for third observation:

$0.0098=k(0.020)^a(0.020)^b$ ....(3)

Expression for rate law for fourth observation:

$0.027=k(0.040)^a(0.040)^b$ ....(4)

Dividing 1 from 2, we get:

$\frac{0.0069}{0.0035}=\frac{k(0.020)^a(0.010)^b}{k(0.010)^a(0.010)^b}\\\\2=2^a\\a=1$

Dividing 2 from 3, we get:

$\frac{0.0098}{0.0069}=\frac{k(0.020)^a(0.020)^b}{k(0.020)^a(0.010)^b}\\\\1.42=2^b\\b=\frac{1}{2}$

Calculation used :

$1.42=2^b\\\log (1.42)=b\log 2\\\log (\frac{1.42}{2})=b\\b=0.5=\frac{1}{2}$

Thus, the rate law becomes:

$\text{Rate}=k[CHCl_3]^1[Cl_2]^{1/2}$

7 0

3 years ago

5 g of gold and 25 g of silver are mixed to form a single-phase ideal solid solution. (a) how many moles of solution are there?

worty [1.4K]

Mole fraction for silver= 0.2317643/0.3079193

= 0.7526787

Mole fraction for gold=0.076155/0.3079193

=0.2473212

What is Molar Fraction?

The mole fraction is the product of the number of molecules of a specific component in a mixture and its total molecular weight. It serves as a means of indicating how concentrated a solution is.

It is a unit of concentration, defined as the product of the moles of a component and the moles of the entire solution. When all the parts of a solution are summed up, their mole fraction equals 1.

molar mass of silver = 107.8682g/mol

Molar mass of gold= 196.96657g/mol

Therefore mole = mass/molar mass

For silver: 25g/107.8682g/mol = 0.2317643mol

For gold: 15g/196.96657g/mol= 0.076155mol

Total number of mole= 0.2317643+0.076155

= 0.30791193mol

Mole fraction for silver= 0.2317643/0.3079193

= 0.7526787

Mole fraction for gold=0.076155/0.3079193

=0.2473212

Learn more about Mole Fraction from given link

brainly.com/question/28590918

#SPJ4

3 0

1 year ago

Explain the difference between molecule and compound

nadya68 [22]

Answer:
A molecule is a group of two or more atoms held together by chemical bonds. A compound is a substance which is formed by two or more different types of elements which are united chemically in a fixed proportion. All molecules are not compounds.

Good luck !

8 0

3 years ago