1. Bor karbid, B4C, bor oksidining grafit bilan yuqori haroratli reaksiyasidan hosil bo'lib, uglerod monooksid yon mahsulot sifatida hosil bóladi B2O3 + c = B4C + co balanslangan tenglamadagi reaktivlar va mahsulotlar uchun eng kichik koeffitsientlar jami

46. ​​Qaysi atomning birinchi ionlanish energiyasi eng yuqori?
(A) Al (B) Si (C) P (D) S
47. Surmaning eng keng tarqalgan ikki oksidlanish darajasi qanday?
(A) –1 va –3 (B) -1 va +2 (C) +3 va -3 (D) +3 va +5
48. Qaysi turlar juftligi uchun radiuslar ko‘proq o‘xshash?
(A) Li va Na (B) Na va Mg (C) Mn va Fe (D) Fe²⁺ va Fe³⁺
49. Bog‘lanish mustahkamligini oshirish tartibida joylashtirilganda qaysi tartib to‘g‘ri?
(A) O–O < S–S < O=O < S=S (B) O–O < S–S < S=S < O=O
(C) S–S < O–O < O=O < S=S (D) S–S < O–O < S=S < O=O
50. Doimiy dipol momentga ega bo'lgan molekulalar quyidagilardan qaysi birini o'z ichiga oladi?
I. HCN II. O₃ III. XeF₂
(A) faqat I (B) faqat I va II (C) faqat II va III (D) I, II va III
51. Oksalat ioni C₂O₄^2- uchun qancha turg'un rezonans shakllarini yozish mumkin?
(A) ikkita (B) uchta (C) to'rtta (D) besh
52. VBR nazariyasiga ko'ra ICl₄^– geometriyasi qanday?
(A) seesaw (B) kvadrat tekislik
(C) tetrahedral (D) T shaklida
53. Molekulyar orbital nazariyaga ko'ra, He–H bog'lanishning bog'lanish tartibi qanday?
(A) ½ (B) ¾ (C) 1 (D) 1 ½
54. Ikki atom fazoda bir-biriga yaqinlashganda, potensial energiya kamayadi, keyin quyidagi diagrammada ko'rsatilganidek ortadi. Bu ikki o'zgarish nimaga bog'liq?
[eslatma: p⁺ =proton, e^–= elektron]

Pasayish (0,40 dan 0,15 nm gacha)	Ortish (0,15 dan 0 nm gacha)
(A) p^+ e^– tortishish kuchaygan	p^+ p^+ itarish kuchaygan
(B) p^+ e^– tortishish kuchaygan	e^- e^- itarish kuchaygan
(C) p^+ p^+ itarishning kamayishi	e^- e^- itarish kuchaygan
(D) p^+ e^– itarishning kamayishi	p^+ p^+ itarish kuchaygan

55. 1-propanol, CH₃CH₂CH₂OH ning yengil oksidlanishi, qaysi moddaning hosil bo'lishiga olib keladi.
(A) propanal, CH₃CH₂CHO.
(B) propan kislotasi, CH₃CH₂COOH.
(C) 2-propanon, CH₃COCH₃.
(D) dipropil efir, CH₃CH₂CH₂OCH₂CH₂CH₃.