Life Sciences
2021 · Paper 1
Take it one question at a time. Try an answer, then check your understanding.
Complete GATE XL 2021 Paper 1 overview, original pages and practice · Timed previous-paper practice
Questions 13–15 of 125. Imported answers require review unless explicitly marked reviewed.
Question 3
Open questionXL-PNAT1 markNeeds review
The time taken by a first order reaction to reach 90% completion is 20 s. The time taken for the reaction to reach 50% completion is ______ s (rounded off to the closest integer).
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Open questionXL-PNAT1 markNeeds review
The ground state energy of an electron in a hydrogen atom is −13.60 eV. The energy of the electron in the third excited state is ______ eV (rounded off to two decimal places).
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 5
Open questionXL-PNAT1 markNeeds review
A solution of a compound shows an absorbance of 0.42 at 275 nm in a cuvette with 0.1 dm light path. The molar absorptivity of the compound is
. The concentration of the compound is ______ × 10
M (rounded off to the closest integer).Log in to check the answer
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