TMS stands for Tetramethylsilane
Formula : Si(CH₃)₄
It is used as internal standard for chemical shift
In TMS all the four methyl groups are similar thus all the 12 hydrogen are chemically equivalent. They will show proton NMR at same level and which will appear as a singlet.
We have defined this singlet to be as reference set as zero.
Generally the other organic compounds show chemical shift downfield.So have positive chemical shift with respect to TMS shift.
That is a chemical change.. Hope I helped!
There are 5.01 × 10-⁷grams in 4.07 x 10¹⁵molecules of calcium hydroxide.
HOW TO CALCULATE MASS:
The mass of a substance can be calculated by multiplying the number of moles in the substance by its molecular mass.
However, given that the number of molecules in calcium hydroxide is 4.07 x 10¹⁵molecules, we need to calculate the number of moles in Ca(OH)2 as follows:
no. of moles of Ca(OH)2 = 4.07 x 10¹⁵ ÷ 6.02 × 10²³
no. of moles = 0.676 × 10-⁸
no. of moles = 6.76 × 10-⁹ moles.
Molar mass of Ca(OH)2 = 74.093 g/mol
Mass of Ca(OH)2 = 74.093 × 6.76 × 10-⁹ moles
Mass = 5.01 × 10-⁷grams.
Therefore, there are 5.01 × 10-⁷grams in 4.07 x 10¹⁵molecules of calcium hydroxide.
Learn more about how to calculate mass at: brainly.com/question/8101390?referrer=searchResults
→
is the balanced chemical equation.
<h3>What is a balanced chemical equation?</h3>
A balanced chemical reaction is an equation that has equal numbers of each type of atom on both sides of the arrow.
Half-reaction method:
Unbalanced chemical equation:
→ 
Oxidation half-reaction:
→ I
Reduction half-reaction:
→ 
Balanced chemical equation:
→ 
Oxidation number method:
Unbalanced chemical equation:
→ 
→ 
→ 
Balanced chemical equation:
→ 
or
→ 
Hence,
→
is the balanced chemical equation.
Learn more about the balanced chemical equation here:
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