过氧化钠(化学式为Na2O2,其中Na元素显+1价)是潜水艇中的制氧剂,它是一种

题型:选择题

问题:

过氧化钠(化学式为Na2O2,其中Na元素显+1价)是潜水艇中的制氧剂,它是一种淡黄色粉末,能与物质R反应生成氧气,反应的化学方程式为:2Na2O2 + 2R=2Na2CO3 + O2,则下列有关判断中,错误的是(    )

A.Na2O2中氧元素化合价为-1价

B.R的化学式为CO2

C.Na2CO3的相对分子质量为106

D.Na2O2中含有氧气分子

考点:化学反应方程式的书写化学图标化学反应方程式的配平化学反应方程式的意义
题型:选择题

糖化血清蛋白主要反映过去多少时间内的平均血糖浓度()

A.2~3天

B.2~3周

C.2~3个月

D.4~8天

E.4~8周

题型:选择题

欲配制100mL1.0 mol/L Na2SO4溶液,正确的方法是 [ ]

①将14.2g Na2SO4溶于100mL水中

②将32.2g Na2SO4·10H2O溶于少量水中,再用水稀释至100mL

③将20mL5.0 mol/L Na2SO4溶液用水稀释至100mL

A.①②   

B.②③   

C.①③    

D.①②③

题型:选择题

Certificates are () documents attesting to the () of a public key to an individual or other entity. They allow verification of the claim that a given public key does in fact belong to a given individual. Certificates help prevent someone from using a phony key to () someone else. In their simplest form, Certificates contain a public key and a name. As commonly used, a Certificate also contains an () date, the name of the CA that issued the Certificate, a serial number, and perhaps other information. Most importantly, it contains the digital () of the certificate issuer. The most widely accepted format for certificates is X.509, thus, Certificates can be read or written by any application complying with X.509.

Certificates help prevent someone from using a phony key to () someone else.

A.impersonate

B.personate

C.damage

D.control

题型:选择题

研究动力来自实务工作者,他们提出问题,自己决定行动方案,专家则作为咨询者协助他们形成理论假设,计划具体行动及评价行动结果。这一行动研究的模式称为( )。

A.合作模式

B.支持模式

C.独立模式

D.专家模式

E.组织模式

题型:选择题

下列哪项不是我国风湿病学会诊断SLE的标准

A.颜面红斑,非畸形关节炎

B.多发性浆膜炎

C.肾脏病变—蛋白尿

D.抗双链DNA抗体阳性

E.血沉增快

更多题库